Digital pathology for reporting histopathology samples, including cancer screening samples - definitive evidence from a multisite study.

AIMS: To conduct a definitive multicentre comparison of digital pathology (DP) with light microscopy (LM) for reporting histopathology slides including breast and bowel cancer screening samples. METHODS: A total of 2024 cases (608 breast, 607 GI, 609 skin, 200 renal) were studied, including 207 breast and 250 bowel cancer screening samples. Cases were examined by four pathologists (16 study pathologists across the four speciality groups), using both LM and DP, with the order randomly assigned and 6 weeks between viewings. Reports were compared for clinical management concordance (CMC), meaning identical diagnoses plus differences which do not affect patient management. Percentage CMCs were computed using logistic regression models with crossed random-effects terms for case and pathologist. The obtained percentage CMCs were referenced to 98.3% calculated from previous studies. RESULTS: For all cases LM versus DP comparisons showed the CMC rates were 99.95% [95% confidence interval (CI) = 99.90-99.97] and 98.96 (95% CI = 98.42-99.32) for cancer screening samples. In speciality groups CMC for LM versus DP showed: breast 99.40% (99.06-99.62) overall and 96.27% (94.63-97.43) for cancer screening samples; [gastrointestinal (GI) = 99.96% (99.89-99.99)] overall and 99.93% (99.68-99.98) for bowel cancer screening samples; skin 99.99% (99.92-100.0); renal 99.99% (99.57-100.0). Analysis of clinically significant differences revealed discrepancies in areas where interobserver variability is known to be high, in reads performed with both modalities and without apparent trends to either. CONCLUSIONS: Comparing LM and DP CMC, overall rates exceed the reference 98.3%, providing compelling evidence that pathologists provide equivalent results for both routine and cancer screening samples irrespective of the modality used.

Activation of a cGAS-STING-mediated immune response predicts response to neoadjuvant chemotherapy in early breast cancer.

BACKGROUND: The DNA-damage immune-response (DDIR) signature is an immune-driven gene expression signature retrospectively validated as predicting response to anthracycline-based therapy. This feasibility study prospectively evaluates the use of this assay to predict neoadjuvant chemotherapy response in early breast cancer. METHODS: This feasibility study assessed the integration of a novel biomarker into clinical workflows. Tumour samples were collected from patients receiving standard of care neoadjuvant chemotherapy (FEC + /-taxane and anti-HER2 therapy as appropriate) at baseline, mid- and post-chemotherapy. Baseline DDIR signature scores were correlated with pathological treatment response. RNA sequencing was used to assess chemotherapy/response-related changes in biologically linked gene signatures. RESULTS: DDIR signature reports were available within 14 days for 97.8% of 46 patients (13 TNBC, 16 HER2 + ve, 27 ER + HER2-ve). Positive scores predicted response to treatment (odds ratio 4.67 for RCB 0-1 disease (95% CI 1.13-15.09, P = 0.032)). DDIR positivity correlated with immune infiltration and upregulated immune-checkpoint gene expression. CONCLUSIONS: This study validates the DDIR signature as predictive of response to neoadjuvant chemotherapy which can be integrated into clinical workflows, potentially identifying a subgroup with high sensitivity to anthracycline chemotherapy. Transcriptomic data suggest induction with anthracycline-containing regimens in immune restricted, "cold" tumours may be effective for immune priming. TRIAL REGISTRATION: Not applicable (non-interventional study). CRUK Internal Database Number 14232.

Bronchus-like Structures in Ovarian Teratomas: Report of a Series of a Previously Unreported Phenomenon With Potential For Misdiagnosis.

We report 10 cases of a previously undescribed lesion within ovarian teratomas which we designate bronchus-like structures. The lesions occurred in patients aged 16 to 56 yr (mean: 36) and involved the left ovary (n=5) or right ovary (n=5). Nine cases were mature teratomas (dermoid cysts/mature cystic teratomas or mature solid teratomas), 1 with somatic malignant transformation, and 1 was an immature teratoma. The bronchus-like structures ranged in size from 2.5 to 10 mm and were unifocal (7 cases) or multifocal (3 cases). The morphology was relatively constant in all cases and characterised by a well-formed bronchus surrounded by glandular structures, some of which were dilated, separated by stroma containing a variable amount of smooth muscle. In all but 1 case, a proportion of the glands contained abundant foamy cytoplasm. There was little or no nuclear atypia or mitotic activity. At low-power, the glands often had a somewhat "infiltrative" appearance and one case was originally diagnosed as a "pulmonary-type" adenocarcinoma arising in a dermoid cyst. In all cases, there was diffuse staining of the bronchus and glands with TTF1 and Napsin A, confirming the cell lineage. Follow-up in 4 cases (18-130 mo; median: 64 mo) showed no evidence of recurrence; 1 patient died from an unrelated malignancy. In reporting this apparently rare but possibly underrecognized benign lesion arising within ovarian teratomas, we discuss the differential diagnosis and stress that pathologists should be aware of this phenomenon in order to avoid an erroneous diagnosis of malignancy.

Exploration of Factors Predictive of At-risk Fathers' Participation in a Pilot Study of an Augmented Evidence-Based Parent Training Program: A Mixed Methods Approach.

There has been burgeoning parenting intervention research specifically addressing fathers in recent decades. Corresponding research examining their participation and engagement in evidence-based parent training programs, which have almost exclusively targeted mothers, is just emerging. The current study used mixed methods to examine factors that influenced completion of an augmented version of an evidence-based child maltreatment prevention program developed for male caregivers called SafeCare Dad to Kids (Dad2K) in a pilot study. The current sample comprised 50 male caregivers (Mage = 29.42 years, SD = 8.18) of a child between the ages of 2 and 5 years. Fathers participated in a baseline assessment and were considered program completers (n = 27) if they participated in the program's six home visiting sessions. A subsample of completers (n = 11) was recruited to participate in qualitative interviews that provided in-depth information about fathers' experiences in Dad2K. Logistic regression indicated that, in the context of other demographic predictors, fathers with an education beyond high school were over 5 times more likely to complete Dad2K program compared to fathers with a high school education or less. Qualitative analyses revealed that interviewed father completers were motivated to enroll and participate in a fathering program because of an interest to learn and obtain skills to make them a better parent. Fathers with a high school education or less may require additional engagement strategies to help proactively encourage their enrollment and completion of parent training programs.

What factors influence cellular pathologists' confidence in case reporting?

Histopathology is a challenging interpretive discipline, and the level of confidence a pathologist has in their diagnosis is known to vary, which is conveyed descriptively in pathology reports. There has been little study to accurately quantify pathologists' diagnostic confidence or the factors that influence it. In this study involving sixteen pathologists from six NHS trusts, we assessed diagnostic confidence across multiple variables and four specialties. Each case was reported by four pathologists, with each pathologist reporting each case twice (on light microscopy (LM) and digital pathology (DP)). For each diagnosis, pathologists recorded their confidence on a 7-point Likert scale. This provided 16,187 diagnoses and associated confidence scores for analysis. All variables investigated were found to be significantly predictive of diagnostic confidence, except level of pathologist experience. Confidence was lower for difficult to report cases, cases where there was inter- and intra-pathologist variation in the diagnosis, and cases where the pathologist made an incorrect diagnosis. Confidence was higher, although nominally, for LM diagnoses than DP (rate ratio 1.09 (95% CI 1.01-1.18), p = 0.035), although results indicate pathologists are confident to report on DP. Lowest confidence scores were seen in areas of known diagnostic complexity and cases with quality issues. High confidence in incorrect diagnoses were almost invariably attributed to interpretive diagnostic differences which occurred across both rare and common lesions. The results highlight the value of external quality control schemes and the benefits of selective peer review when reporting.

Impact of COVID-19 on the practice of breast pathologists: a survey of breast pathologists in the UK and Ireland.

AIMS: There is little information on the impact of COVID-19 on breast pathologists. This survey assessed the effect of the COVID-19 pandemic on UK and Ireland-based breast pathologists to optimise working environments and ensure preparedness for potential future pandemics. METHODS: A 35-question survey during the first wave of COVID-19 infections in the UK including questions on workload, working practices, professional development, training, health and safety and well-being was distributed to consultant breast pathologists and responses collected anonymously. RESULTS: There were 135 responses from breast pathologists based in the UK and Ireland. Most participants (75.6%) stated that their workload had decreased and their productivity dropped. 86/135 (63.7%) were given the option of working from home and 36% of those who did reported improved efficiency. Multidisciplinary team meetings largely moved to virtual platforms (77.8%) with fewer members present (41.5%). Online education, including webinars and courses, was utilised by 92.6%. 16.3% of pathologists reported shortages of masks, visors or gowns as the the most common health and safety concern. COVID-19 had a significant negative impact on the physical and mental health of 33.3% of respondents. A small number of pathologists (10.4%) were redeployed and/or retrained. CONCLUSION: The UK and Ireland breast pathologists adapted to the rapid change and maintained service delivery despite the significant impact of the pandemic on their working practices and mental health. It is important to apply flexible working patterns and environments that improve productivity and well-being. The changes suggested should be considered for long-term shaping of breast pathology services.

Concordance of HER2-low scoring in breast carcinoma among expert pathologists in the United Kingdom and the republic of Ireland -on behalf of the UK national coordinating committee for breast pathology.

BACKGROUND: Recent clinical evidence showed that breast cancer with low HER2 expression levels responded to trastuzumab deruxtecan therapy. The HER2-low cancers comprise immunohistochemistry (IHC) score 1+ and 2+ ISH non-amplified tumours, currently classified as HER2 negative. Little data exists on the reproducibility of pathologists reporting of HER2-low cancer. PATIENT AND METHODS: Sixteen expert pathologists of the UK National Coordinating Committee for Breast Pathology scored 50 digitally scanned HER2 IHC slides. The overall level of agreement, Fleiss multiple-rater kappa statistics and Cohen's Kappa were calculated. Cases with low concordance were re-scored by the same pathologists after a washout period. RESULTS: Absolute agreement was achieved in 6% of cases, all of which scored 3+. Poor agreement was found in 5/50 (10%) of cases. This was due to heterogeneous HER2 expression, cytoplasmic staining and low expression spanning the 10% cut-off value. Highest concordance (86%) was achieved when scores were clustered as 0 versus others. Improvement in kappa of overall agreement was achieved when scores 1+ and 2+ were combined. Inter-observer agreement was moderate to substantial in the whole cohort but fair to moderate in the HER2-low group. Similarly, consensus-observer agreement was substantial to almost perfect in the whole cohort and moderate to substantial in the HER2-low group. CONCLUSION: HER2-low breast cancer suffers from lower concordance among expert pathologists. While most cases can reproducibly be classified, a small proportion (10%) remained challenging. Refining the criteria for reporting and consensus scoring will help select appropriate patients for targeted therapy.

Endometrial adenocarcinoma with signet ring cells: report of two cases of an extremely rare phenomenon.

The presence of signet ring cells in a carcinoma within the uterine corpus strongly raises the possibility of a metastasis from a primary tumor in the breast, gastrointestinal tract, or elsewhere. Signet ring cells are extremely rare in primary endometrial adenocarcinomas with only a single prior case report. We report 2 cases of primary endometrial adenocarcinoma, one of mucinous and the other of endometrioid type, with a significant component of signet ring cells. One of the neoplasms arose within adenomyosis. In reporting these cases, we illustrate that the presence of signet ring cells does not preclude a primary endometrial adenocarcinoma.We discuss signet ring cells in the endometrium.

Multifocal breast cancers are more prevalent in BRCA2 versus BRCA1 mutation carriers.

Multifocal (MF)/multicentric (MC) breast cancer is generally considered to be where two or more breast tumours are present within the same breast, and is seen in ~10% of breast cancer cases. This study investigates the prevalence of multifocality/multicentricity in a cohort of BRCA1/2 mutation carriers with breast cancer from Northern Ireland via cross-sectional analysis. Data from 211 women with BRCA1/2 mutations (BRCA1-91, BRCA2-120) and breast cancer were collected including age, tumour focality, size, type, grade and receptor profile. The prevalence of multifocality/multicentricity within this group was 25% but, within subgroups, prevalence amongst BRCA2 carriers was more than double that of BRCA1 carriers (p = 0.001). Women affected by MF/MC tumours had proportionately higher oestrogen receptor positivity (p = 0.001) and lower triple negativity (p = 0.004). These observations are likely to be driven by the higher BRCA2 mutation prevalence observed within this cohort. The odds of a BRCA2 carrier developing MF/MC cancer were almost four-fold higher than a BRCA1 carrier (odds ratio: 3.71, CI: 1.77-7.78, p = 0.001). These findings were subsequently validated in a second, large independent cohort of patients with BRCA-associated breast cancers from a UK-wide multicentre study. This confirmed a significantly higher prevalence of MF/MC tumours amongst BRCA2 mutation carriers compared with BRCA1 mutation carriers. This has important implications for clinicians involved in the treatment of BRCA2-associated breast cancer, both in the diagnostic process, in ensuring that tumour focality is adequately assessed to facilitate treatment decision-making, and for breast surgeons, particularly if breast conserving surgery is being considered as a treatment option for these patients.

The impact of SafeCare® Dads to Kids program on father maltreatment risk and involvement: Outcomes and lessons learned from an efficacy trial.

Child Maltreatment (CM) is a public health problem, and experts recommend parent training programs as a prevention method. Few programs target fathers, even though male caregivers are involved as perpetrators in approximately 45% of substantiated CM cases. This study examines the efficacy of an adapted version of SafeCare (Dad2K) with marginalized fathers. Participants include a convenience sample of fathers with children ages 2-5 years. Fathers (n=99) were randomized to an 1) intervention group (SafeCare Dad2K) or to a 2) comparison group (receiving parenting information in the mail). Quantitative data were collected at baseline, post-intervention (7-weeks post-baseline), and 3-months post-intervention. Qualitative data (semi-structured interviews) were collected from 11 intervention father completers following the second quantitative data collection timepoint. Multi-level modeling results indicated no statistically significant time-by-treatment findings for father involvement (b=0.03, 95% confidence interval [CI]: -0.03, 0.08, p=0.38), total corporal punishment (b=-0.03, 95% CI: -0.47, 0.41, p=0.89), or neglect (b=-0.13, 95% CI: -1.93, 1.68, p=0.89). Qualitative findings indicated that Dad2K completers exhibited positive knowledge and behavioral change related to parenting. Study limitations, lessons learned from this formative work, and recommendations for future research are discussed.

Automated tumor analysis for molecular profiling in lung cancer.

The discovery and clinical application of molecular biomarkers in solid tumors, increasingly relies on nucleic acid extraction from FFPE tissue sections and subsequent molecular profiling. This in turn requires the pathological review of haematoxylin & eosin (H&E) stained slides, to ensure sample quality, tumor DNA sufficiency by visually estimating the percentage tumor nuclei and tumor annotation for manual macrodissection. In this study on NSCLC, we demonstrate considerable variation in tumor nuclei percentage between pathologists, potentially undermining the precision of NSCLC molecular evaluation and emphasising the need for quantitative tumor evaluation. We subsequently describe the development and validation of a system called TissueMark for automated tumor annotation and percentage tumor nuclei measurement in NSCLC using computerized image analysis. Evaluation of 245 NSCLC slides showed precise automated tumor annotation of cases using Tissuemark, strong concordance with manually drawn boundaries and identical EGFR mutational status, following manual macrodissection from the image analysis generated tumor boundaries. Automated analysis of cell counts for % tumor measurements by Tissuemark showed reduced variability and significant correlation (p < 0.001) with benchmark tumor cell counts. This study demonstrates a robust image analysis technology that can facilitate the automated quantitative analysis of tissue samples for molecular profiling in discovery and diagnostics.

MAPK signaling in neurodegeneration: influences of flavonoids and of nitric oxide.

Oxidative and nitrosative stress is increasingly associated with the pathology of neurodegeneration and aging. The molecular mechanisms underlying oxidative/nitrosative stress-induced neuronal damage are emerging and appear to involve a mode of death in which mitogen-activated protein kinase (MAPK) signaling pathways are strongly implicated. Thus, attention is turning towards the modulation of intracellular signaling as a therapeutic approach against neurodegeneration. Both endogenous and dietary agents have been suggested as potent modulators of intracellular signal transduction, e.g. nitric oxide and flavonoids, respectively. This review addresses recent findings on the biological effects of flavonoids and nitric oxide in neurodegeneration and aims to elucidate the rationale for their prospective use as modulators of cellular signal transduction.

Adrenal sarcomatoid carcinoma: a case report and review of the literature.

Adrenocortical sarcomatoid carcinoma (ASC) is an extremely rare variant of adrenocortical carcinoma (ACC). Its relative rarity and its characteristic histological pattern of both epithelioid and sarcomatoid components may pose diagnostic challenges which influence treatment. Here, we report a case of ASC in a 58 year-old man presenting with increasing abdominal pain and associated abdominal bloating with a large right adrenal mass detected by computed tomographic scan (CT). To our knowledge, only eleven prior cases of ASC have been reported in the literature. Here, we discuss the clinical, radiological and histopathological findings in our case, review the literature on ASCs and offer opinion on best management.

Low-grade ovarian serous neoplasms (low-grade serous carcinoma and serous borderline tumor) associated with high-grade serous carcinoma or undifferentiated carcinoma: report of a series of cases of an unusual phenomenon.

Recent literature has suggested a dual pathway of ovarian serous carcinogenesis, with most serous carcinomas falling into 1 of 2 categories, low grade and high grade. These are considered to represent 2 distinct tumor types with a different underlying pathogenesis and associated with different molecular events, clinical behavior, and prognosis. Low-grade serous carcinoma is thought to evolve in many instances from a preexisting serous borderline tumor and cystadenoma. Given the distinct pathogenesis and different molecular events, it is expected that the coexistence of low-grade and high-grade serous carcinoma would be rare or may even be mutually exclusive; moreover, there are very few reported examples in the literature. We report a series of 7 cases in patients aged 34 to 78 years in whom ovarian low-grade serous carcinoma (4 cases, including 3 with associated serous borderline tumor), serous borderline tumor (2 cases), or seromucinous borderline tumor (1 case) was associated with a high-grade carcinoma, either high-grade serous (5 cases) or undifferentiated carcinoma (2 cases). The low-grade and high-grade components coexisted in the original neoplasm in 4 cases, and the high-grade component was present only in recurrence in 3 cases. In both instances, the undifferentiated carcinoma had a focal rhabdoid morphology, and alternative primary sites of tumor were excluded by a combination of clinical, radiologic, and pathologic parameters. We illustrate that low-grade serous carcinoma or serous borderline tumor ("low-grade" serous neoplasms) may rarely be associated with, and probably give rise to, a high-grade carcinoma, either high-grade serous or undifferentiated carcinoma. The coexistence of a low-grade serous neoplasm and undifferentiated carcinoma can be regarded as a form of dedifferentiation. p53 was diffusely positive in 4 of 6 high-grade carcinomas, which raises the possibility that secondary Tp53 mutation is important in high-grade transformation in some of these cases. WT1 was negative in the 2 undifferentiated carcinomas, and PAX8 was positive in 1, suggesting that the latter marker is more useful in helping to confirm a Mullerian origin in dedifferentiated low-grade serous neoplasms.

Pulmonary-type adenocarcinoma and signet ring mucinous adenocarcinoma arising in an ovarian dermoid cyst: report of a unique case.

Dermoid cysts are common benign ovarian germ cell neoplasms. Occasionally, one of the mature elements undergoes malignant transformation resulting in the formation of a somatic malignancy; most commonly this is squamous carcinoma. We report a unique case where 2 separate malignancies arose within a dermoid cyst, one a signet ring mucinous adenocarcinoma and the other a pulmonary-type adenocarcinoma. There have been only occasional earlier case reports of a possible pulmonary-type adenocarcinoma arising in a dermoid cyst. In the case we report, the pulmonary-type adenocarcinoma was closely associated with a bronchial structure and exhibited diffuse positive immunohistochemical staining with TTF1, PE10, and napsin A. Molecular studies revealed no evidence of epidermal growth factor receptor mutation, a molecular alteration which may be found in primary pulmonary adenocarcinoma.

Unusual morphological features of uterine leiomyomas treated with progestogens.

BACKGROUND: Uterine leiomyomas are extremely common in surgical pathology practice and in the vast majority there are no issues in diagnosis. Progestogens are widely prescribed drugs for a variety of indications, including abnormal uterine bleeding, and are often given to women with leiomyomas but the pathological features of leiomyomas treated with progestogens are poorly described. METHODS: We report the pathological features in eight cases of uterine leiomyomas in women who had been treated with oral progestogens or a progestogen-containing intrauterine device; all cases were received in consultation because the features raised concern for leiomyosarcoma, smooth muscle tumour of uncertain malignant potential or a benign leiomyoma with unusual features. Additionally, we reviewed a series of cases of uterine leiomyomas (n=99) in women who exhibited progestogenic effects in the endometrium. RESULTS: The morphological features in the consult cases, which were widespread and marked and which varied somewhat from case to case, included small and/or large areas of infarct-type necrosis (sometimes mimicking coagulative tumour cell necrosis) with surrounding increased cellularity, mitotic activity, nuclear pyknosis, cytoplasmic eosinophilia, epithelioid morphology, stromal oedema, haemorrhage, and myxoid change and infiltration by CD56 positive granulated lymphocytes. Sometimes the features resulted in an almost deciduoid appearance. Similar features were present to a minor degree in significant numbers of the additional series of cases. CONCLUSIONS: Pathologists should be aware of these progestogen-associated features when reporting uterine leiomyomas whether or not the clinician has indicated that the woman is taking progestogens since otherwise a diagnosis of leiomyosarcoma or smooth muscle tumour of uncertain malignant potential may be rendered. Useful features in suggesting a benign leiomyoma, in addition to recognition of the morphological features described which, in combination, are characteristic of progestogens, are the lack of true nuclear atypia and the low mitotic activity away from the abnormal areas.

Nitric oxide and cell signaling pathways in mitochondrial-dependent apoptosis.

Nitric oxide, generated by endogenous nitric oxide synthases or nitric oxide donors, can promote or prevent apoptosis induced by diverse pro-apoptotic stimuli in cell culture models. Both mitochondrial-dependent and -independent apoptotic signaling pathways mediate this dichotomous cellular response to nitric oxide. The molecular mechanisms behind these effects are complex and involve a number of nitrogen oxide-related species that are more reactive than nitric oxide itself. The local cellular environment plays a dynamic role in determining the nature and concentration of these species. Important components of the microenvironment include: the cellular redox state, glutathione, transition metals and the presence of other oxygen- and nitrogen-centered radicals. In particular, redox-sensitive nitrosating species are favorably generated under physiological conditions and capable of modifying multiple cell signaling pathways through reversible S-nitrosation reactions. Cytochrome c release from mitochondria is an important mechanism for the activation of caspase-3 and the initiation of cell death in response to 'intrinsic' pro-apoptotic stimuli, including oxidative and nitrosative stress. In turn, caspases and mitogen associated protein kinases may modulate cytochrome c release through their effects on the Bcl-2 family of proteins. This review will focus on (i) the importance of the cellular environment in determining the fate of nitric oxide and (ii) the ability of S-nitrosation to regulate mitochondrial-dependent apoptosis at the level of mitochondrial bioenergetics, cytochrome c release, caspases, mitogen associated protein kinases, and the Bcl-2 family of proteins.

c-Jun N-terminal kinase (JNK)-mediated modulation of brain mitochondria function: new target proteins for JNK signalling in mitochondrion-dependent apoptosis.

The molecular mechanisms underlying the initiation and control of the release of cytochrome c during mitochondrion-dependent apoptosis are thought to involve the phosphorylation of mitochondrial Bcl-2 and Bcl-x(L). Although the c-Jun N-terminal kinase (JNK) has been proposed to mediate the phosphorylation of Bcl-2/Bcl-x(L) the mechanisms linking the modification of these proteins and the release of cytochrome c remain to be elucidated. This study was aimed at establishing interdependency between JNK signalling and mitochondrial apoptosis. Using an experimental model consisting of isolated, bioenergetically competent rat brain mitochondria, these studies show that (i) JNK catalysed the phosphorylation of Bcl-2 and Bcl-x(L) as well as other mitochondrial proteins, as shown by two-dimensional isoelectric focusing/SDS/PAGE; (ii) JNK-induced cytochrome c release, in a process independent of the permeability transition of the inner mitochondrial membrane (imPT) and insensitive to cyclosporin A; (iii) JNK mediated a partial collapse of the mitochondrial inner-membrane potential (Deltapsim) in an imPT- and cyclosporin A-independent manner; and (iv) JNK was unable to induce imPT/swelling and did not act as a co-inducer, but as an inhibitor of Ca-induced imPT. The results are discussed with regard to the functional link between the Deltapsim and factors influencing the permeability transition of the inner and outer mitochondrial membranes. Taken together, JNK-dependent phosphorylation of mitochondrial proteins including, but not limited to, Bcl-2/Bcl-x(L) may represent a potential of the modulation of mitochondrial function during apoptosis.