Including the Reason for Use on Prescriptions Sent to Pharmacists: Scoping Review.

BACKGROUND: In North America, although pharmacists are obligated to ensure prescribed medications are appropriate, information about a patient's reason for use is not a required component of a legal prescription. The benefits of prescribers including the reason for use on prescriptions is evident in the current literature. However, it is not standard practice to share this information with pharmacists. OBJECTIVE: Our aim was to characterize the research on how including the reason for use on a prescription impacts pharmacists. METHODS: We performed an interdisciplinary scoping review, searching literature in the fields of health care, informatics, and engineering. The following databases were searched between December 2018 and January 2019: PubMed, Institute of Electrical and Electronics Engineers (IEEE), Association for Computing Machinery (ACM), International Pharmaceutical Abstracts (IPA), and EMBASE. RESULTS: A total of 3912 potentially relevant articles were identified, with 9 papers meeting the inclusion criteria. The studies used different terminology (eg, indication, reason for use) and a wide variety of study methodologies, including prospective and retrospective observational studies, randomized controlled trials, and qualitative interviews and focus groups. The results suggest that including the reason for use on a prescription can help the pharmacist catch more errors, reduce the need to contact prescribers, support patient counseling, impact communication, and improve patient safety. Reasons that may prevent prescribers from adding the reason for use information are concerns about workflow and patient privacy. CONCLUSIONS: More research is needed to understand how the reason for use information should be provided to pharmacists. In the limited literature to date, there is a consensus that the addition of this information to prescriptions benefits patient safety and enables pharmacists to be more effective. Future research should use an implementation science or theory-based approach to improve prescriber buy-in and, consequently, adoption.

"My pharmacist": Creating and maintaining relationship between physicians and pharmacists in primary care settings.

BACKGROUND: Pharmacists and physicians are being increasingly encouraged to adopt a collaborative approach to patient care, and delivery of health services. Strong collaboration between pharmacists and physicians is known to improve patient safety, however pharmacists have expressed difficulty in developing interprofessional working relationships. There is not a significant body of knowledge around how relationships influence how and when pharmacists and physicians communicate about patient care. OBJECTIVES: This paper examines how pharmacists and primary care physicians communicate with each other, specifically when they have or do not have an established relationship. METHODS: Thematic analysis of data from semi-structured interviews with nine primary care physicians and 25 pharmacists, we examined how pharmacists and physicians talk about their roles and responsibilities in primary care and how they build relationships with each other. RESULTS: We found that both groups of professionals communicated with each other in relation to the perceived scope of their practice and roles. Three emerging themes emerged in the data focusing on (1) the different ways physicians communicate with pharmacists; (2) insights into barriers discussed by pharmacists; and (3) how relationships shape collaboration and interactions. Pharmacists were also responsible for initiating the relationship as they relied on it more than the physicians. The presence or absence of a personal connection dramatically impacts how comfortable healthcare professionals are with collaboration around care. CONCLUSION: The findings support and extend the existing literature on pharmacist-physician collaboration, as it relates to trust, relationship, and role. The importance of strong communication is noted, as is the necessity of improving ways to build relationships to ensure strong interprofessional collaboration.

Exploring the role of teams and technology in patients' medication decision making.

OBJECTIVES: We know little about how electronic health records (EHRs) should be designed to help patients, pharmacists, and physicians participate in interprofessional shared decision making. We used a qualitative approach to understand better how patients make decisions with their health care team, how this information influences decision making about their medications, and finally, how this process can be improved through the use of EHRs. DESIGN: Participants from 4 regions across Canada took part in a semistructured interview and completed a brief demographic survey. The interview transcripts were thematically analyzed by means of the multidisciplinary framework method. SETTINGS AND PARTICIPANTS: Thirty participants, 18 years of age and older with at least one chronic illness, were recruited from across Canada. We interviewed participants in their homes, at the school of pharmacy, or another location of their choosing. RESULTS: We identified 4 main themes: (1) complexity of patient decision making: who, where, what, when, why; (2) relationships with physicians and pharmacists: who do I trust for what?; (3) accessing health information for decision making: how much and from where?; and (4) patients' methods of managing information for health decision making. Across the themes, participants appreciated expert advice from professionals and wanted to be informed about all options, despite concerns about limited knowledge. EHRs were perceived as a potential solution to many of the barriers identified. CONCLUSION: Patients make decisions with their health care providers as well as with family and friends. The pharmacist and physicians play different roles in helping patients in making decisions. We found that making EHRs accessible not only to health care providers but also to patients can provide a cohesive and clear context for making medication-related decisions. EHRs may facilitate clear communication, foster interprofessional understanding, and improve patient access to their health information. Future research should examine how to develop EHRs that are adaptive to user needs and desires.

Physician and Pharmacist Medication Decision-Making in the Time of Electronic Health Records: Mixed-Methods Study.

BACKGROUND: Primary care needs to be patient-centered, integrated, and interprofessional to help patients with complex needs manage the burden of medication-related problems. Considering the growing problem of polypharmacy, increasing attention has been paid to how and when medication-related decisions should be coordinated across multidisciplinary care teams. Improved knowledge on how integrated electronic health records (EHRs) can support interprofessional shared decision-making for medication therapy management is necessary to continue improving patient care. OBJECTIVE: The objective of our study was to examine how physicians and pharmacists understand and communicate patient-focused medication information with each other and how this knowledge can influence the design of EHRs. METHODS: This study is part of a broader cross-Canada study between patients and health care providers around how medication-related decisions are made and communicated. We visited community pharmacies, team-based primary care clinics, and independent-practice family physician clinics throughout Ontario, Nova Scotia, Alberta, and Quebec. Research assistants conducted semistructured interviews with physicians and pharmacists. A modified version of the Multidisciplinary Framework Method was used to analyze the data. RESULTS: We collected data from 19 pharmacies and 9 medical clinics and identified 6 main themes from 34 health care professionals. First, Interprofessional Shared Decision-Making was not occurring and clinicians made decisions based on their understanding of the patient. Physicians and pharmacists reported indirect Communication, incomplete Information specifically missing insight into indication and adherence, and misaligned Processes of Care that were further compounded by EHRs that are not designed to facilitate collaboration. Scope of Practice examined professional and workplace boundaries for pharmacists and physicians that were internally and externally imposed. Physicians decided on the degree of the Physician-Pharmacist Relationship, often predicated by colocation. CONCLUSIONS: We observed limited communication and collaboration between primary care providers and pharmacists when managing medications. Pharmacists were missing key information around reason for use, and physicians required accurate information around adherence. EHRs are a potential tool to help clinicians communicate information to resolve this issue. EHRs need to be designed to facilitate interprofessional medication management so that pharmacists and physicians can move beyond task-based work toward a collaborative approach.

Technology for fostering intergenerational connectivity: scoping review protocol.

BACKGROUND: The simultaneous increase in geographically dispersed families and general decrease in engagement in local communities is resulting in fewer opportunities for youth and older adults interact in meaningful ways. Technology is becoming increasingly pervasive and flexible and providing new opportunities to foster intergenerational connection that can be implemented and evaluated across a multitude of populations and contexts. What research has been done in this area is spread across disciplines and what aspects of technologies could make them more effective is not well understood. METHOD: The scoping review will be completed in five stages: (1) identifying the research question, (2) identifying relevant studies, (3) selecting studies, (4) charting the data, and (5) collating, summarizing, and reporting the results. Comprehensive descriptive data from each study will be presented along with an analysis of similarities and differences in research from different disciplines. DISCUSSION: This scoping review focuses on a search of the literature to gain an understanding of what technologies have been used specifically for fostering intergenerational connectivity and to establish what future directions for research could be. To the authors' knowledge, it is the first scoping review of its kind.

Non-invasive brain stimulation interventions for management of chronic central neuropathic pain: a scoping review protocol.

INTRODUCTION: Pain can affect people regardless of age, gender or ethnicity. Chronic central neuropathic pain (CCNP) is a debilitating condition that affects populations such as stroke survivors, amputees, spinal cord injury patients and patients with multiple sclerosis, with prevalence rates between 30% and 80%. This condition can be caused by a lesion or disease affecting the somatosensory system. CCNP is notoriously drug resistant, and few effective CCNP treatment or management strategies exist. The emergence of non-invasive brain stimulation and neuromodulation techniques provide novel avenues for managing chronic central neuropathic pain. This scoping review aims to systematically identify the methods and effectiveness of non-invasive brain stimulation techniques for treating and managing chronic central neuropathic pain. METHODS AND ANALYSIS: The following databases will be searched systematically: PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Institute of Electric and Electronic Engineers (IEEE), Association of Computing Machinary (ACM) and Scopus. Additional literature will be identified by searching the reference lists of identified studies. Studies will include reviews and original research in both published and grey literatures. Two reviewers will independently screen identified studies for final inclusion. A quantitative analysis on the intervention type, application and efficacy will be synthesised along with a qualitative analysis to describe the effectiveness of each intervention. ETHICS AND DISSEMINATION: No primary data will be collected and hence formal ethics review is not required. The results of the scoping review will be presented at relevant national and international conferences, published in a peer-reviewed journal and provided to the stakeholders with plain language to be posted on their websites. This scoping review will provide a foundation to guide the development of future primary research on non-invasive brain stimulation and CCNP.

Behavior Change Techniques Present in Wearable Activity Trackers: A Critical Analysis.

BACKGROUND: Wearable activity trackers are promising as interventions that offer guidance and support for increasing physical activity and health-focused tracking. Most adults do not meet their recommended daily activity guidelines, and wearable fitness trackers are increasingly cited as having great potential to improve the physical activity levels of adults. OBJECTIVE: The objective of this study was to use the Coventry, Aberdeen, and London-Refined (CALO-RE) taxonomy to examine if the design of wearable activity trackers incorporates behavior change techniques (BCTs). A secondary objective was to critically analyze whether the BCTs present relate to known drivers of behavior change, such as self-efficacy, with the intention of extending applicability to older adults in addition to the overall population. METHODS: Wearing each device for a period of 1 week, two independent raters used CALO-RE taxonomy to code the BCTs of the seven wearable activity trackers available in Canada as of March 2014. These included Fitbit Flex, Misfit Shine, Withings Pulse, Jawbone UP24, Spark Activity Tracker by SparkPeople, Nike+ FuelBand SE, and Polar Loop. We calculated interrater reliability using Cohen's kappa. RESULTS: The average number of BCTs identified was 16.3/40. Withings Pulse had the highest number of BCTs and Misfit Shine had the lowest. Most techniques centered around self-monitoring and self-regulation, all of which have been associated with improved physical activity in older adults. Techniques related to planning and providing instructions were scarce. CONCLUSIONS: Overall, wearable activity trackers contain several BCTs that have been shown to increase physical activity in older adults. Although more research and development must be done to fully understand the potential of wearables as health interventions, the current wearable trackers offer significant potential with regard to BCTs relevant to uptake by all populations, including older adults.

A systematic review of interventions to improve medication information for low health literate populations.

BACKGROUND: Health literacy is a barrier to accurately understanding medication information. Current medication information is too difficult to understand for low health literate populations, which imposes a higher risk of misinterpreting prescription label instructions, dosage, duration, frequency, warning labels, written information and verbal pharmacist counseling. OBJECTIVES: The primary objective of this paper was to systematically review the evidence on interventions for improving medication knowledge and adherence for low health literate populations. METHODS: A database search of PubMed, Embase, International Pharmaceutical Abstracts, Web of Science, Cochrane Library, CINAHL, PsycINFO, and Scopus databases from the start of each database to studies published prior to March 30, 2015. Studies were included if they explicitly stated they included low health literate populations, included outcome measures for knowledge and/or adherence, focused on medication information, were written in English and were available in full text. Full text papers were excluded if there was no clear mention of an intervention being studied, if the intervention had no focus on any of the domains of health literacy, and if the authors did not specify the inclusion of patients with low health literacy. RESULTS: The review identified 1553 titles, 1009 abstracts, and 168 full text articles and included 47 articles in the final review. Of the 47 included studies, 70.2% (33/47) were published in the United States and 87.2 (41/47) were published between 2005 and 2014. Studies were grouped into six different types of interventions 1) written information 2) visual information 3) verbal information 4) label/medication bottle 5) reminder systems and 6) educational programs and services. Results demonstrate significant improvement of knowledge in 27 of 37 interventions and a significant improvement of adherence in 19 of 26 interventions. CONCLUSIONS: Interventions designed to support low health literate populations can improve patients' medication knowledge and adherence. The most effective interventions include additional aids that enforce written information, information that is personalized, information that is easy to navigate and tools that can be accessed when needed.

Acceptance of Commercially Available Wearable Activity Trackers Among Adults Aged Over 50 and With Chronic Illness: A Mixed-Methods Evaluation.

BACKGROUND: Physical inactivity and sedentary behavior increase the risk of chronic illness and death. The newest generation of "wearable" activity trackers offers potential as a multifaceted intervention to help people become more active. OBJECTIVE: To examine the usability and usefulness of wearable activity trackers for older adults living with chronic illness. METHODS: We recruited a purposive sample of 32 participants over the age of 50, who had been previously diagnosed with a chronic illness, including vascular disease, diabetes, arthritis, and osteoporosis. Participants were between 52 and 84 years of age (mean 64); among the study participants, 23 (72%) were women and the mean body mass index was 31 kg/m(2). Participants tested 5 trackers, including a simple pedometer (Sportline or Mio) followed by 4 wearable activity trackers (Fitbit Zip, Misfit Shine, Jawbone Up 24, and Withings Pulse) in random order. Selected devices represented the range of wearable products and features available on the Canadian market in 2014. Participants wore each device for at least 3 days and evaluated it using a questionnaire developed from the Technology Acceptance Model. We used focus groups to explore participant experiences and a thematic analysis approach to data collection and analysis. RESULTS: Our study resulted in 4 themes: (1) adoption within a comfort zone; (2) self-awareness and goal setting; (3) purposes of data tracking; and (4) future of wearable activity trackers as health care devices. Prior to enrolling, few participants were aware of wearable activity trackers. Most also had been asked by a physician to exercise more and cited this as a motivation for testing the devices. None of the participants planned to purchase the simple pedometer after the study, citing poor accuracy and data loss, whereas 73% (N=32) planned to purchase a wearable activity tracker. Preferences varied but 50% felt they would buy a Fitbit and 42% felt they would buy a Misfit, Jawbone, or Withings. The simple pedometer had a mean acceptance score of 56/95 compared with 63 for the Withings, 65 for the Misfit and Jawbone, and 68 for the Fitbit. To improve usability, older users may benefit from devices that have better compatibility with personal computers or less-expensive Android mobile phones and tablets, and have comprehensive paper-based user manuals and apps that interpret user data. CONCLUSIONS: For older adults living with chronic illness, wearable activity trackers are perceived as useful and acceptable. New users may need support to both set up the device and learn how to interpret their data.

Using a collaborative research approach to develop an interdisciplinary research agenda for the study of mobile health interventions for older adults.

BACKGROUND: Seniors with chronic diseases are often called on to self-manage their conditions. Mobile health (mHealth) tools may be a useful strategy to help seniors access health information at the point of decision-making, receive real-time feedback and coaching, and monitor health conditions. However, developing successful mHealth interventions for seniors presents many challenges. One of the key challenges is to ensure the scope of possible research questions includes the diverse views of seniors, experts and the stakeholder groups who support seniors as they manage chronic disease. OBJECTIVE: Our primary objective was to present a case-study of a collaborative research approach to the development of an interdisciplinary research agenda. Our secondary objectives were to report on the results of a nominal group technique (NGT) approach used generate research questions and to assess the success of including non-academic researchers to enrich the scope, priority, and total number of possible research questions. METHODS: We invited researchers and stakeholders to participate in a full day meeting that included rapid-style presentations by researchers, health care professionals, technology experts, patients and community groups followed by group discussions. An NGT was used to establish group consensus on the following question: In your opinion, what research needs to be done to better understand the effectiveness, usability and design of mobile health apps and devices for older adults? RESULTS: Overall, the collaborative approach was a very successful strategy to bring together a diverse group of participants with the same end goal. The 32 participants generated 119 items in total. The top three research questions that emerged from the NGT were related to adoption, the need for high quality tools and the digital divide. Strong sub-themes included privacy and security, engagement and design. The NGT also helped us include the perspectives information from non-academic researchers that would not have been captured if the process had been limited to the research team. CONCLUSIONS: Developing ways for patients and other stakeholders to have a voice when it comes to developing patient awareness as related to mHealth may guide future research into engagement, ownership, usability and design. It is our intention that our paper be used and adapted by other researchers to engage small or vulnerable populations often excluded from mHealth research and design.

The intermediate-activity (L597V)BRAF mutant acts as an epistatic modifier of oncogenic RAS by enhancing signaling through the RAF/MEK/ERK pathway.

(L597V)BRAF mutations are acquired somatically in human cancer samples and are frequently coincident with RAS mutations. Germline (L597V)BRAF mutations are also found in several autosomal dominant developmental conditions known as RASopathies, raising the important question of how the same mutation can contribute to both pathologies. Using a conditional knock-in mouse model, we show that endogenous expression of (L597V)Braf leads to approximately twofold elevated Braf kinase activity and weak activation of the Mek/Erk pathway. This is associated with induction of RASopathy hallmarks including cardiac abnormalities and facial dysmorphia but is not sufficient for tumor formation. We combined (L597V)Braf with (G12D)Kras and found that (L597V)Braf modified (G12D)Kras oncogenesis such that fibroblast transformation and lung tumor development were more reminiscent of that driven by the high-activity (V600E)Braf mutant. Mek/Erk activation levels were comparable with those driven by (V600E)Braf in the double-mutant cells, and the gene expression signature was more similar to that induced by (V600E)Braf than (G12D)Kras. However, unlike (V600E)Braf, Mek/Erk pathway activation was mediated by both Craf and Braf, and ATP-competitive RAF inhibitors induced paradoxical Mek/Erk pathway activation. Our data show that weak activation of the Mek/Erk pathway underpins RASopathies, but in cancer, (L597V)Braf epistatically modifies the transforming effects of driver oncogenes.

Analysis of chick (Gallus gallus) middle ear columella formation.

BACKGROUND: The chick middle ear bone, the columella, provides an accessible model in which to study the tissue and molecular interactions necessary for induction and patterning of the columella, as well as associated multiple aspects of endochondral ossification. These include mesenchymal condensation, chondrogenesis, ossification of the medial footplate and shaft, and joint formation between the persistent cartilage of the extracolumella and ossified columella. Middle and external ear defects are responsible for approximately 10% of congenital hearing defects. Thus, understanding the morphogenesis and the molecular mechanisms of the formation of the middle ear is important to understanding normal and abnormal development of this essential component of the hearing apparatus. RESULTS: The columella, which arises from proximal ectomesenchyme of the second pharyngeal arch, is induced and patterned in a dynamic multi-step process. From the footplate, which inserts into the inner ear oval window, the shaft spans the pneumatic middle ear cavity, and the extracolumella inserts into the tympanic membrane. Through marker gene and immunolabeling analysis, we have determined the onset of each stage in the columella's development, from condensation to ossification. Significantly, a single condensation with the putative shaft and extracolumella arms already distinguishable is observed shortly before initiation of five separate chondrogenic centers within these structures. Ossification begins later, with periosteum formation in the shaft and, unexpectedly, a separate periosteum in the footplate. CONCLUSIONS: The data presented in this study document the spatiotemporal events leading to morphogenesis of the columella and middle ear structures and provide the first gene expression data for this region. These data identify candidate genes and facilitate future functional studies and elucidation of the molecular mechanisms of columella formation.

CRAF autophosphorylation of serine 621 is required to prevent its proteasome-mediated degradation.

The CRAF protein kinase regulates proliferative, differentiation, and survival signals from activated RAS proteins to downstream effectors, most often by inducing MEK/ERK activation. A well-established model of CRAF regulation involves RAS-mediated translocation of CRAF to the plasma membrane, where it is activated by a series of events including phosphorylation. Here we have discovered a new mode of regulation that occurs prior to this step. By creating a kinase-defective version of CRAF in mice or by use of the RAF inhibitor sorafenib, we show that CRAF must first undergo autophosphorylation of serine 621 (S621). Autophosphorylation occurs in cis, does not involve MEK/ERK activation, and is essential to ensure the correct folding and stability of the protein. In the absence of S621 phosphorylation, CRAF is degraded by the proteasome by mechanisms that do not uniquely rely on the E3 ubiquitin ligase CHIP.

Expression of endogenous oncogenic V600EB-raf induces proliferation and developmental defects in mice and transformation of primary fibroblasts.

Mutations of the human B-RAF gene are detected in approximately 8% of cancer samples, primarily in cutaneous melanomas (70%). The most common mutation (90%) is a valine-to-glutamic acid mutation at residue 600 (V600E; formerly V599E according to previous nomenclature). Using a Cre/Lox approach, we have generated a conditional knock-in allele of (V600E)B-raf in mice. We show that widespread expression of (V600E)B-Raf cannot be tolerated in embryonic development, with embryos dying approximately 7.5 dpc. Directed expression of mutant (V600E)B-Raf to somatic tissues using the IFN-inducible Mx1-Cre mouse strain induces a proliferative disorder and bone marrow failure with evidence of nonlymphoid neoplasia of the histiocytic type leading to death within 4 weeks of age. However, expression of mutant B-Raf does not alter the proliferation profile of all somatic tissues. In primary mouse embryonic fibroblasts, expression of endogenous (V600E)B-Raf induces morphologic transformation, increased cell proliferation, and loss of contact inhibition. Thus, (V600E)B-Raf is able to induce several hallmarks of transformation in some primary mouse cells without evidence for the involvement of a cooperating oncogene or tumor suppressor gene.

A-Raf and Raf-1 work together to influence transient ERK phosphorylation and Gl/S cell cycle progression.

The Raf/MEK/ERK (extracellular regulated kinase) signal transduction pathway controls the ability of cells to respond to proliferative, apoptotic, migratory and differentiation signals. We have investigated the combined contribution of A-Raf and Raf-1 isotypes to signalling through this pathway by generating mice with knockout mutations of both A-raf and raf-1 genes. Double knockout (DKO) mice have a more severe phenotype than single null mutations of either gene, dying in embryogenesis at E10.5. The DKO embryos show no changes in apoptosis, but staining for Ki67 indicates a generalized reduction in proliferation. DKO mouse embryonic fibroblasts (MEFs) exhibit a delayed ability to enter S phase of the cell cycle. This is associated with a reduction in levels of transiently induced MEK and ERK phosphorylation and reduced expression of c-Fos and cyclin Dl. Levels of sustained ERK phosphorylation are not significantly altered. Thus, Raf-1 and A-Raf have a combined role in controlling physiological transient ERK activation and in maintenance of cell cycle progression at its usual rate.

Raf proteins and cancer: B-Raf is identified as a mutational target.

A recent report has shown that activating mutations in the BRAF gene are present in a large percentage of human malignant melanomas and in a proportion of colon cancers. The vast majority of these mutations represent a single nucleotide change of T-A at nucleotide 1796 resulting in a valine to glutamic acid change at residue 599 within the activation segment of B-Raf. This exciting new discovery is the first time that a direct association between any RAF gene and human cancer has been reported. Raf proteins are also indirectly associated with cancer as effectors of activated Ras proteins, oncogenic forms of which are present in approximately one-third of all human cancers. BRAF and RAS mutations are rarely both present in the same cancers but the cancer types with BRAF mutations are similar to those with RAS mutations. This has been taken as evidence that the inappropriate regulation of the downstream ERKs (the p42/p44 MAP kinases) is a major contributing factor in the development of these cancers. Recent studies in mice with targeted mutations of the raf genes have confirmed that B-Raf is a far stronger activator of ERKs than its better studied Raf-1 homologue, even in cell types in which the protein is barely expressed. The explanation for this lies in a number of key differences in the regulation of B-Raf and Raf-1 activity. Constitutive phosphorylation of serine 445 of B-Raf leads to this protein having a higher basal kinase activity than Raf-1. Phosphorylation of threonine 598 and serine 601 within the activation loop of B-Raf at the plasma membrane also regulates its activity. The V599E mutation is thought to mimic these phosphorylations, resulting in a protein with high activity, leading to constitutive ERK activation. B-Raf now provides a critical new target to which drugs for treating malignant melanoma can be developed and, with this in mind, it is now important to gain clear insight into the biochemical properties of this relatively little characterised protein.

ERK signalling and oncogene transformation are not impaired in cells lacking A-Raf.

Previous studies have indicated an important role for the Raf family of protein kinases in controlling cellular responses to extracellular stimuli and activated oncogenes, through their ability to activate the MEK/ERKs. To investigate the specific role of A-Raf in this process we generated A-Raf deficient mouse embryonic fibroblasts (MEFs) and embryonic stem (ES) cells by gene targeting and characterized their ability to undergo proliferation, differentiation, apoptosis, ERK activation, and transformation by oncogenic Ras and Src. The A-Raf deficient cells are not disrupted for any of these processes, despite the fact that this protein is normally expressed at high levels in both cell types. This implies either that A-Raf plays no role in MEK/ERK activation, that its function is fully compensated by other Raf proteins or MEK kinases or that its role in MEK/ERK activation is highly tissue-specific. Interestingly, B-Raf and Raf-1 activity towards MEK as measured by the immunoprecipitation kinase cascade assay are both significantly increased in the A-Raf deficient MEFs.