Real-World Adverse Events Associated with Encapsulated Benzoyl Peroxide/Tretinoin, 3%/0.1%, and Encapsulated Benzoyl Peroxide, 5.

Encapsulated benzoyl peroxide, 5%, for rosacea and a combined formulation of encapsulated benzoyl peroxide/tretinoin, 3%/0.1%, for acne vulgaris, utilize microencapsulation, a process by which active pharmaceutical agents are enclosed in inert, permeable silica shells that provide a buffer between the drug and the skin. The silica shells allow a gradual release of the drug while also allowing combinations of active ingredients that would not otherwise be possible. This technology allows benzoyl peroxide and tretinoin to be combined in the same vehicle without risking the benzoyl peroxide-mediated oxidative destruction of tretinoin. In the current study, we queried the Galderma pharmacovigilance database to quantify and categorize adverse events associated with using these products in the USA during a 12-month period from May 2022 through April 2023. The adverse events were generally mild and restricted to local irritation, pruritus, burning sensation, and erythema. The real-world incidence and type of adverse events reported by the community for encapsulated benzoyl peroxide/tretinoin, 3%/0.1%, and benzoyl peroxide, 5%, were consistent with the safety and tolerability findings from the phase III clinical studies of these treatments.

Trifarotene Reduces Risk for Atrophic Acne Scars: Results from A Phase 4 Controlled Study.

BACKGROUND: Atrophic acne scarring often accompanies acne vulgaris. The efficacy of topical retinoids for treatment of acne is well documented; however, evidence for use in atrophic acne scars is limited. METHODS: In this randomized, split-face, double-blind study, subjects (age: 17-34 years, N = 121) with moderate-to-severe facial acne, with acne scars present, were treated with either trifarotene 50 µg/g or vehicle once daily for 24 weeks. Efficacy was assessed by absolute and percent change from baseline in atrophic acne scar counts, Scar Global assessment (SGA), and IGA success rates as well as acne lesion counts. RESULTS: At week 24, a statistically significantly greater reduction in the mean absolute change from baseline in the total atrophic scar count was noted in the trifarotene- vs vehicle-treated area (- 5.9 vs - 2.7; p < 0.0001) with differences between sides noted as early as week 2 (- 1.5 vs - 0.7; p = 0.0072). The SGA success rate was higher in the trifarotene side at week 12 (14.9% vs 5.0%, P < 0.05) and improved through week 24 (31.3% vs 8.1%, P < 0.001). Similarly, at week 24, the IGA success rate was higher with trifarotene (63.6% vs 31.3%, P < 0.0001) along with reductions in total (70% vs 45%) and inflammatory (76% vs 48%) lesion counts. The incidence of treatment-emergent adverse events was 5.8% (trifarotene) and 2.5% (vehicle); most common (> 1%) was skin tightness (1.7% vs 0.8%), and all events were mild to moderate in severity. CONCLUSIONS: Trifarotene was effective and well tolerated in treating moderate-to-severe facial acne and reducing atrophic acne scars, with reduction of total atrophic scar count as early as week 2. TRIAL REGISTRATION: Clinicaltrials.gov NCT04856904.

Relationship between the Dental Aesthetic Index and Discrepancy Index.

OBJECTIVE: To establish the association between malocclusion severity and orthodontic case complexity as assessed by the Dental Aesthetic Index (DAI) and the American Board of Orthodontics Discrepancy Index (ABO-DI), respectively. DESIGN: Cross-sectional study. SETTING: Pre-treatment dental casts and radiographs from 500 individuals (294 women and 206 men; mean age = 26.06 ± 11.58 years) were randomly selected from the orthodontics department of a private university. METHODS: Malocclusion severity was assessed using DAI and case complexity was evaluated with ABO-DI. Three previously calibrated operators performed the measurements. Spearman's correlation analysis, Mann-Whitney U test, Kruskal-Wallis test and a linear generalised model were used for statistical evaluation (P < 0.05 was considered significant). RESULTS: Although the correlation (r = 0.45; P < 0.0001) between malocclusion severity and case complexity was moderate, strong evidence of an association (P < 0.001) between dichotomised DAI and ABO-DI total scores was observed. The linear generalised model showed that for each point of increase in DAI score, the ABO-DI score increased an average of 0.3624 points (P < 0.0001). CONCLUSION: An association between malocclusion severity and case complexity is suggested. A linear generalised model could be used to predict the complexity of the case from the malocclusion severity (DAI score).

Men With Intellectual Disabilities Who Have Offended Sexually.

PURPOSE OF REVIEW: We review extant and new research focusing on assessment and treatment of men with intellectual disabilities (ID) who have offended sexually. New research findings are applied and integrated with classic assessment and treatment approaches, providing an overview of evidence-based practices. RECENT FINDINGS: New research has explored healthy sexuality among people with intellectual disabilities, including making evidence-based sexual information cognitively accessible for people with ID. Research has begun to include men with ID in studies of actuarial risk assessment and dynamic treatment needs and identify forms of sexual deviation. New research has identified the need for access to treatment materials better tailored to clients' cognitive level, as well as understanding normal sexuality among people with ID. The recent research further develops our understanding of men with ID who offended sexually and demonstrates similarities between men with and without ID who have offended sexually. The new research findings provide evidence-based support and guidance for clinicians working with this set of clients and suggest optimism for more positive outcomes as studies from across the globe are focusing on working with men with ID who have offended sexually.

Medical Writing Competency Model - Section 1: Functions, Tasks, and Activities.

This article provides Section 1 of the 2017 Edition 2 Medical Writing Competency Model that describes the core work functions and associated tasks and activities related to professional medical writing within the life sciences industry. The functions in the Model are scientific communication strategy; document preparation, development, and finalization; document project management; document template, standard, format, and style development and maintenance; outsourcing, alliance partner, and client management; knowledge, skill, ability, and behavior development and sharing; and process improvement. The full Model also includes Section 2, which covers the knowledge, skills, abilities, and behaviors needed for medical writers to be effective in their roles; Section 2 is presented in a companion article. Regulatory, publication, and other scientific writing as well as management of writing activities are covered. The Model was developed to aid medical writers and managers within the life sciences industry regarding medical writing hiring, training, expectation and goal setting, performance evaluation, career development, retention, and role value sharing to cross-functional partners.

Medical Writing Competency Model - Section 2: Knowledge, Skills, Abilities, and Behaviors.

This article provides Section 2 of the 2017 Edition 2 Medical Writing Competency Model that describes the knowledge, skills, abilities, and behaviors that professional medical writers need in order to perform effectively within the life sciences industry. What a medical writer should know, what they should be able to do, and how they should use this knowledge and these skills to facilitate their primary work function is a focus. Regulatory, publication, and other scientific writing as well as management of writing activities are covered. The full Model also includes Section 1, which covers the core work functions and associated tasks and activities related to professional medical writing within the life sciences industry; Section 1 is included in a companion article. The Model was developed to aid medical writers and managers within the life sciences industry regarding medical writing hiring, training, expectation and goal setting, performance evaluation, career development, retention, and role value sharing to cross-functional partners.

Phosphorylation of P27 by AKT is required for inhibition of cell cycle progression in cholangiocarcinoma.

BACKGROUND AND OBJECTIVE: P27 is a putative tumor suppressor when located in the nucleus and AKT is an inhibitor of P27 which promotes growth of cholangiocarcinoma. We hypothesized that AKT-dependent phosphorylation at the P27 nuclear localization sequence T157 leads to nuclear export of P27, and thus loss of its tumor suppressive function. This study investigated whether loss of cell cycle regulation in cholangiocarcinoma due to subcellular localization of P27. METHODS: Human cholangiocarcinoma cells were transfected with AKT. P27 was tagged with yellow fluorescence protein. Cell cycle progression was determined by flow cytometry. Migration and invasion of was measured by transwell assay. RESULTS: Overexpression of wildtype P27 or P27-T157A in Mz-ChA-1 cells resulted in G1 arrest; expression of myr-AKT caused translocation of P27-YFP and endogenous P27 from the nucleus to the cytoplasm, leading to inhibition of P27-dependent G1 arrest; the AKT inhibitor and expression of dnAKT increased P27-YFP accumulation in the nucleus and promoted G1 arrest. In contrast, cells expressing YFP-P27-T157A or P27-YFP accumulated only in the nucleus. Co-expression of myr-AKT failed to induce P27-YFP translocation to the cytoplasm or inhibit G1 arrest. Overexpression of P27-T157A significantly increased migration and invasion. CONCLUSIONS: Cholangiocarcinoma growth is associated with nuclear export of P27 that is due to AKT-mediated phosphorylation of P27 at T157.

Adapalene/Benzoyl Peroxide Gel 0.3%/2.5%: A Safe and Effective Acne Therapy in All Skin Phototypes.

BACKGROUND: Acne affects individuals of all races and ethnicities; however, lighter and darker skin phototypes face different treatment challenges that may affect treatment response and tolerability. This analysis investigated possible differences in the efficacy and safety of the fixed dose combination of 0.3% adapalene with 2.5% benzoyl peroxide (A/BPO gel 0.3%/2.5%) in subjects with Fitzpatrick Skin Types (FST) I-VI.

METHODS: This was a post-hoc analysis of a Phase 3, multicenter, randomized, double-blind, parallel-group study of moderate to severe acne in subjects with FST I-VI. Subjects received A/BPO gel 0.3%/2.5%, A/BPO gel 0.1%/2.5% (benchmark), or vehicle, once daily for 12 weeks. Efficacy measurements included success rate (IGA of Clear or Almost Clear), change in inflammatory and noninflammatory lesions from baseline to week 12, safety, and tolerability. The intent to treat (ITT) and safety populations were analyzed. Demographics and disposition were analyzed with descriptive statistics; categorical variables by frequency and percentage; and continuous variables with means, medians, minimum, maximum, and standard deviations.

RESULTS: The A/BPO gel 0.3%/2.5% treatment group included 128 subjects with FST I-III, and 89 subjects with FST IV-VI. At week 12, A/BPO gel 0.3%/2.5% was safe, tolerable, and significantly superior to vehicle for all FST and severity groups in inflammatory and noninflammatory lesion reduction (P less than equal to .05). Compared to baseline, 32% of subjects with FST I-III were clear or almost clear, compared to 7% in the vehicle group (P=.001). In FST IV-VI, 28% of subjects were clear or almost clear, compared to 15% for vehicle (P=NS). In all treatment groups and skin phototypes, week 12 tolerability scores were similar to baseline scores, and tolerability scores for most subjects of all skin phototypes were "none" or "mild" for all measures.

SUMMARY: We report that the fixed dose combination of A/BPO gel 0.3%/2.5% is efficacious and safe in patients with FST I-VI with moderate and severe inflammatory acne.

Clinicaltrials.gov registry: NCT01880320

J Drugs Dermatol. 2017;16(6):574-581.

Growth Arrest Specific 2 (GAS2) is a Critical Mediator of Germ Cell Cyst Breakdown and Folliculogenesis in Mice.

In the mouse ovary, the primordial follicle pool is established through a diverse array of signaling pathways and tissue remodeling events. Growth arrest specific gene two (GAS2) is a highly conserved cytoskeleton-associated protein whose in vivo function remains unclear. In Drosophila, loss of the GAS2 homolog, Pigs, results in infertility. We demonstrate herein that, in the mouse ovary, GAS2 is expressed in the stromal cells surrounding the oocyte cysts on 16.5 dpc, and in stromal cells surrounding growing follicles during juvenile and adult life. We have generated genetically engineered mice with inactivated Gas2. Gas2 homozygous mutant mice are viable but have severely impaired fertility in females, in which oocyte cyst breakdown is disrupted and follicle growth is impaired, with significantly reduced numbers of large antral follicles and corpora lutea. In these mutant mice, the organization of the basal lamina surrounding developing follicles is severely defective at multiple stages of folliculogenesis. We also found that Notch signaling activity was altered in ovaries from Gas2 null mice around the time of birth and during follicular development later in life. These results indicate that GAS2 is a critical and novel regulator of tissue remodeling in the ovary during oocyte cyst breakdown and folliculogenesis.

Recruited metastasis suppressor NM23-H2 attenuates expression and activity of peroxisome proliferator-activated receptor δ (PPARδ) in human cholangiocarcinoma.

BACKGROUND: Peroxisome proliferator-activated receptor δ (PPARδ) is a versatile regulator of distinct biological processes and overexpression of PPARδ in cancer may be partially related to its suppression of its own co-regulators. AIMS: To determine whether recruited suppressor proteins bind to and regulate PPARδ expression, activity and PPARδ-dependent cholangiocarcinoma proliferation. METHODS: Yeast two-hybrid assays were done using murine PPARδ as bait. PPARδ mRNA expression was determined by qPCR. Protein expression was measured by western blot. Immunohistochemistry and fluorescence microscopy were used to determine PPARδ expression and co-localization with NDP Kinase alpha (NM23-H2). Cell proliferation assays were performed to determine cell numbers. RESULTS: Yeast two-hybrid screening identified NM23-H2 as a PPARδ binding protein and their interaction was confirmed. Overexpressed PPARδ or treatment with the agonist GW501516 resulted in increased cell proliferation. NM23-H2 siRNA activated PPARδ luciferase promoter activity, upregulated PPARδ RNA and protein expression and increased GW501516-stimulated CCA growth. Overexpression of NM23-H2 inhibited PPARδ luciferase promoter activity, downregulated PPARδ expression and AKT phosphorylation and reduced GW501516-stimulated CCA growth. CONCLUSIONS: We report the novel association of NM23-H2 with PPARδ and the negative regulation of PPARδ expression by NM23-H2 binding to the C-terminal region of PPARδ. These findings provide evidence that the metastasis suppressor NM23-H2 is involved in the regulation of PPARδ-mediated proliferation.

A device for fully automated on-site process monitoring and control of trihalomethane concentrations in drinking water.

An instrument designed for fully automated on-line monitoring of trihalomethane concentrations in chlorinated drinking water is presented. The patented capillary membrane sampling device automatically samples directly from a water tap followed by injection of the sample into a gas chromatograph equipped with a nickel-63 electron capture detector. Detailed studies using individual trihalomethane species exhibited method detection limits ranging from 0.01-0.04 µg L(-1). Mean percent recoveries ranged from 77.1 to 86.5% with percent relative standard deviation values ranging from 1.2 to 4.6%. Out of more than 5200 samples analyzed, 95% of the concentration ranges were detectable, 86.5% were quantifiable. The failure rate was less than 2%. Using the data from the instrument, two different treatment processes were optimized so that total trihalomethane concentrations were maintained at acceptable levels while reducing treatment costs significantly. This ongoing trihalomethane monitoring program has been operating for more than ten months and has produced the longest continuous and most finely time-resolved data on trihalomethane concentrations reported in the literature.

Heterozygous frameshift mutation in keratin 5 in a family with Galli-Galli disease.

BACKGROUND: Reticulate pigmentary disorders include the rare autosomal dominant Galli-Galli disease (GGD) and Dowling-Degos disease (DDD). Clinical diagnosis between some of the subtypes can be difficult due to a degree of overlap between clinical features, therefore analysis at the molecular level may be necessary to confirm the diagnosis. OBJECTIVES: To identify the underlying genetic defect in a 48-year-old Asian-American woman with a clinical diagnosis of GGD. METHODS: Histological analysis was performed on a skin biopsy using haematoxylin-eosin staining. KRT5 (the gene encoding keratin 5) was amplified from genomic DNA and directly sequenced. RESULTS: The patient had a history of pruritus and hyperpigmented erythematous macules and thin papules along the flexor surfaces of her arms, her upper back and neck, axillae and inframammary areas. Hypopigmented macules were seen among the hyperpigmentation. A heterozygous 1-bp insertion mutation in KRT5 (c.38dupG; p.Ser14GlnfsTer3) was identified in the proband. This mutation occurs within the head domain of the keratin 5 protein leading to a frameshift and premature stop codon. CONCLUSIONS: From the histological findings and mutation analysis the individual was identified as having GGD due to haploinsufficiency of keratin 5.

FXR-induced secretion of FGF15/19 inhibits CYP27 expression in cholangiocytes through p38 kinase pathway.

Cholangiocytes, bile duct lining cells, actively adjust the amount of cholesterol and bile acids in bile through expression of enzymes and channels involved in transportation and metabolism of the cholesterol and bile acids. Herein, we report molecular mechanisms regulating bile acid biosynthesis in cholangiocytes. Among the cytochrome p450 (Cyp) enzymes involved in bile acid biosynthesis, sterol 27-hydroxylase (Cyp27) that is the rate-limiting enzyme for the acidic pathway of bile acid biosynthesis expressed in cholangiocytes. Expression of other Cyp enzymes for the basic bile acid biosynthesis was hardly detected. The Cyp27 expression was negatively regulated by a hydrophobic bile acid through farnesoid X receptor (FXR), a nuclear receptor activated by bile acid ligands. Activated FXR exerted the negative effects by inducing an expression of fibroblast growth factor 15/19 (FGF15/19). Similar to its repressive function against cholesterol 7α-hydroxylase (Cyp7a1) expression in hepatocytes, secreted FGF15/19 triggered Cyp27 repression in cholangiocytes through interaction with its cognate receptor fibroblast growth factor receptor 4 (FGFR4). The involvements of FXR and FGFR4 for the bile acid-induced Cyp27 repression were confirmed in vivo using knockout mouse models. Different from the signaling in hepatocytes, wherein the FGF15/19-induced repression signaling is mediated by c-Jun N-terminal kinase (JNK), FGF15/19-induced Cyp27 repression in cholangiocytes was mediated by p38 kinase. Thus, the results collectively suggest that cholangiocytes may be able to actively regulate bile acid biosynthesis in cholangiocytes and even hepatocyte by secreting FGF15/19. We suggest the presence of cholangiocyte-mediated intrahepatic feedback loop in addition to the enterohepatic feedback loop against bile acid biosynthesis in the liver.

Antisense oligonucleotide suppression of human IGF-1R inhibits the growth and survival of in vitro cultured epithelial ovarian cancer cells.

BACKGROUND: Preclinical evaluation of the anti-neoplastic activity of antisense oligonucleotide (AS) suppression of human insulin-like growth factor I receptor (IGF-IR) in human epithelial ovarian cancer (EOC). METHODS: Ovarian cancer cells from 36 patients with EOC were investigated under serum-free tissue culture conditions. IGF-I production was evaluated by standard ELISA. IGF-IR and phosphorylated IRS-1, AKT, and MAP kinase expression and protein levels were evaluated by immunohistochemistry and Western blotting. Cancer cell growth and proliferation assays were performed in triplicates using MTT assay. Apoptosis was evaluated by TUNNEL assay. RESULTS: All ovarian cancer tissue samples tested produced IGF-I and expressed IGF-IR, supporting the existence of an autocrine loop. Treatment of primary ovarian cancer cell lines with an IGF-1R AS inhibited growth and proliferation and decreased clonogenicity in soft agar assay. AS treatment was demonstrated to inhibit the expression of IGF-1R and decrease the concentration of phosphorylated IRS-1, AKT, and MAP kinase signaling protein downstream of the IGF-IR. We also observed that the IGF-1R AS sensitized cancer cell lines to cisplatin in vitro through the PI3K pathway. CONCLUSIONS: IGF-IR enhances the proliferation and tumorigenicity of human ovarian cancer cells and inhibition of IGF-IR by AS oligonucleotide treatment potentiates the activity of cisplatin in vitro. Therefore, IGF-1R is a potential molecular target in ovarian cancer.

Extra-group mating increases inbreeding risk in a cooperatively breeding bird.

In many cooperatively breeding species, females mate extra-group, the adaptive value of which remains poorly understood. One hypothesis posits that females employ extra-group mating to access mates whose genotypes are more dissimilar to their own than their social mates, so as to increase offspring heterozygosity. We test this hypothesis using life history and genetic data from 36 cooperatively breeding white-browed sparrow weaver (Plocepasser mahali) groups. Contrary to prediction, a dominant female's relatedness to her social mate did not drive extra-group mating decisions and, moreover, extra-group mating females were significantly more related to their extra-group sires than their social mates. Instead, dominant females were substantially more likely to mate extra-group when paired to a dominant male of low heterozygosity, and their extra-group mates (typically dominants themselves) were significantly more heterozygous than the males they cuckolded. The combined effects of mating with extra-group males of closer relatedness, but higher heterozygosity resulted in extra-group-sired offspring that were no more heterozygous than their within-group-sired half-siblings. Our findings are consistent with a role for male-male competition in driving extra-group mating and suggest that the local kin structure typical of cooperative breeders could counter potential benefits to females of mating extra-group by exposing them to a risk of inbreeding.

Production of a mouse line with a conditional Crim1 mutant allele.

Crim1 is a developmentally expressed, transmembrane protein essential for normal embryonic development. We generated mice engineered to contain a Crim1 conditional null allele by flanking exons three and four of Crim1 with unidirectional LoxP sites. After crossing Crim1+/FLOX mice with a CMV-Cre line, a Crim1+/Δflox colony was established after germline transmission of the deleted allele. We then analyzed genomic DNA, mRNA transcripts, and protein expression from Crim1Δflox/Δflox null mice to confirm the nature of the genomic lesion. Crim1Δflox/Δflox mice displayed phenotypes similar to those previously described for a Crim1 gene-trap mutant, Crim1KST264/KST264, including perinatal lethality, digit syndactyly, eye, and kidney abnormalities, with varying penetrance and severity. The production of a conditional mutant allele represents a valuable resource for the study of the tissue-specific roles for Crim1, and for understanding the pleimorphic phenotypes associated with Crim1 mutation.

Environmental constraints influencing survival of an African parasite in a north temperate habitat: effects of temperature on development within the host.

The monogenean Protopolystoma xenopodis has been established in Wales for >40 years following introduction with Xenopus laevis from South Africa. This provides an experimental system for determining constraints affecting introduced species in novel environments. Parasite development post-infection was followed at 15, 20 and 25°C for 15 weeks and at 10°C for ⩾1 year and correlated with temperatures recorded in Wales. Development was slowed/arrested at ⩽10°C which reflects habitat conditions for >6 months/year. There was wide variation in growth at constant temperature (body size differing by >10 times) potentially attributable in part to genotype-specific host-parasite interactions. Parasite density had no effect on size but host sex did: worms in males were 1·8 times larger than in females. Minimum time to patency was 51 days at 25°C and 73 days at 20°C although some infections were still not patent at both temperatures by 105 days p.i. In Wales, fastest developing infections may mature within one summer (about 12 weeks), possibly accelerated by movements of hosts into warmer surface waters. Otherwise, development slows/stops in October-April, delaying patency to about 1 year p.i., while wide variation in developmental rates may impose delays of 2 years in some primary infections and even longer in secondary infections.

Environmental constraints influencing survival of an African parasite in a north temperate habitat: effects of temperature on egg development.

Factors affecting survival of parasites introduced to new geographical regions include changes in environmental temperature. Protopolystoma xenopodis is a monogenean introduced with the amphibian Xenopus laevis from South Africa to Wales (probably in the 1960s) where low water temperatures impose major constraints on life-cycle processes. Effects were quantified by maintenance of eggs from infections in Wales under controlled conditions at 10, 12, 15, 18, 20 and 25°C. The threshold for egg viability/ development was 15°C. Mean times to hatching were 22 days at 25°C, 32 days at 20°C, extending to 66 days at 15°C. Field temperature records provided calibration of transmission schedules. Although egg production continues year-round, all eggs produced during >8 months/ year die without hatching. Output contributing significantly to transmission is restricted to 10 weeks (May-mid-July). Host infection, beginning after a time lag of 8 weeks for egg development, is also restricted to 10 weeks (July-September). Habitat temperatures (mean 15·5°C in summer 2008) allow only a narrow margin for life-cycle progress: even small temperature increases, predicted with 'global warming', enhance infection. This system provides empirical data on the metrics of transmission permitting long-term persistence of isolated parasite populations in limiting environments.

Loss of spindle assembly checkpoint-mediated inhibition of Cdc20 promotes tumorigenesis in mice.

Genomic instability is a hallmark of human cancers. Spindle assembly checkpoint (SAC) is a critical cellular mechanism that prevents chromosome missegregation and therefore aneuploidy by blocking premature separation of sister chromatids. Thus, SAC, much like the DNA damage checkpoint, is essential for genome stability. In this study, we report the generation and analysis of mice carrying a Cdc20 allele in which three residues critical for the interaction with Mad2 were mutated to alanine. The mutant Cdc20 protein (AAA-Cdc20) is no longer inhibited by Mad2 in response to SAC activation, leading to the dysfunction of SAC and aneuploidy. The dysfunction could not be rescued by the additional expression of another Cdc20 inhibitor, BubR1. Furthermore, we found that Cdc20(AAA/AAA) mice died at late gestation, but Cdc20(+/AAA) mice were viable. Importantly, Cdc20(+/AAA) mice developed spontaneous tumors at highly accelerated rates, indicating that the SAC-mediated inhibition of Cdc20 is an important tumor-suppressing mechanism.