The enteric nervous system relays psychological stress to intestinal inflammation.

Mental health profoundly impacts inflammatory responses in the body. This is particularly apparent in inflammatory bowel disease (IBD), in which psychological stress is associated with exacerbated disease flares. Here, we discover a critical role for the enteric nervous system (ENS) in mediating the aggravating effect of chronic stress on intestinal inflammation. We find that chronically elevated levels of glucocorticoids drive the generation of an inflammatory subset of enteric glia that promotes monocyte- and TNF-mediated inflammation via CSF1. Additionally, glucocorticoids cause transcriptional immaturity in enteric neurons, acetylcholine deficiency, and dysmotility via TGF-ß2. We verify the connection between the psychological state, intestinal inflammation, and dysmotility in three cohorts of IBD patients. Together, these findings offer a mechanistic explanation for the impact of the brain on peripheral inflammation, define the ENS as a relay between psychological stress and gut inflammation, and suggest that stress management could serve as a valuable component of IBD care.

Serotonin reduction in post-acute sequelae of viral infection.

Post-acute sequelae of COVID-19 (PASC, "Long COVID") pose a significant global health challenge. The pathophysiology is unknown, and no effective treatments have been found to date. Several hypotheses have been formulated to explain the etiology of PASC, including viral persistence, chronic inflammation, hypercoagulability, and autonomic dysfunction. Here, we propose a mechanism that links all four hypotheses in a single pathway and provides actionable insights for therapeutic interventions. We find that PASC are associated with serotonin reduction. Viral infection and type I interferon-driven inflammation reduce serotonin through three mechanisms: diminished intestinal absorption of the serotonin precursor tryptophan; platelet hyperactivation and thrombocytopenia, which impacts serotonin storage; and enhanced MAO-mediated serotonin turnover. Peripheral serotonin reduction, in turn, impedes the activity of the vagus nerve and thereby impairs hippocampal responses and memory. These findings provide a possible explanation for neurocognitive symptoms associated with viral persistence in Long COVID, which may extend to other post-viral syndromes.

ß-Hydroxybutyrate suppresses colorectal cancer.

Colorectal cancer (CRC) is among the most frequent forms of cancer, and new strategies for its prevention and therapy are urgently needed1. Here we identify a metabolite signalling pathway that provides actionable insights towards this goal. We perform a dietary screen in autochthonous animal models of CRC and find that ketogenic diets exhibit a strong tumour-inhibitory effect. These properties of ketogenic diets are recapitulated by the ketone body ß-hydroxybutyrate (BHB), which reduces the proliferation of colonic crypt cells and potently suppresses intestinal tumour growth. We find that BHB acts through the surface receptor Hcar2 and induces the transcriptional regulator Hopx, thereby altering gene expression and inhibiting cell proliferation. Cancer organoid assays and single-cell RNA sequencing of biopsies from patients with CRC provide evidence that elevated BHB levels and active HOPX are associated with reduced intestinal epithelial proliferation in humans. This study thus identifies a BHB-triggered pathway regulating intestinal tumorigenesis and indicates that oral or systemic interventions with a single metabolite may complement current prevention and treatment strategies for CRC.

A microbiome-dependent gut-brain pathway regulates motivation for exercise.

Exercise exerts a wide range of beneficial effects for healthy physiology1. However, the mechanisms regulating an individual's motivation to engage in physical activity remain incompletely understood. An important factor stimulating the engagement in both competitive and recreational exercise is the motivating pleasure derived from prolonged physical activity, which is triggered by exercise-induced neurochemical changes in the brain. Here, we report on the discovery of a gut-brain connection in mice that enhances exercise performance by augmenting dopamine signalling during physical activity. We find that microbiome-dependent production of endocannabinoid metabolites in the gut stimulates the activity of TRPV1-expressing sensory neurons and thereby elevates dopamine levels in the ventral striatum during exercise. Stimulation of this pathway improves running performance, whereas microbiome depletion, peripheral endocannabinoid receptor inhibition, ablation of spinal afferent neurons or dopamine blockade abrogate exercise capacity. These findings indicate that the rewarding properties of exercise are influenced by gut-derived interoceptive circuits and provide a microbiome-dependent explanation for interindividual variability in exercise performance. Our study also suggests that interoceptomimetic molecules that stimulate the transmission of gut-derived signals to the brain may enhance the motivation for exercise.

The miR156 juvenility factor and PLETHORA 2 form a regulatory network and influence timing of meristem growth and lateral root emergence.

Plants develop throughout their lives: seeds become seedlings that mature and form fruits and seeds. Although the underlying mechanisms that drive these developmental phase transitions have been well elucidated for shoots, the extent to which they affect the root is less clear. However, root anatomy does change as some plants mature; meristems enlarge and radial thickening occurs. Here, in Arabidopsis thaliana, we show that overexpressing miR156A, a gene that promotes the juvenile phase, increased the density of the root system, even in grafted plants in which only the rootstock had the overexpression genotype. In the root, overexpression of miR156A resulted in lower levels of PLETHORA 2, a protein that affects formation of the meristem and elongation zone. Crossing in an extra copy of PLETHORA 2 partially rescued the effects of miR156A overexpression on traits affecting root architecture, including meristem length and the rate of lateral root emergence. Consistent with this, PLETHORA 2 also inhibited the root-tip expression of another miR156 gene, miR156C. We conclude that the system driving phase change in the shoot affects developmental progression in the root, and that PLETHORA 2 participates in this network.

Targeting lipid nanoparticles to the blood-brain barrier to ameliorate acute ischemic stroke.

Effective delivery of mRNA or small molecule drugs to the brain is a significant challenge in developing treatment for acute ischemic stroke (AIS). To address the problem, we have developed targeted nanomedicine to increase drug concentrations in endothelial cells of the blood-brain barrier (BBB) of the injured brain. Inflammation during ischemic stroke causes continuous neuronal death and an increase in the infarct volume. To enable targeted delivery to the inflamed BBB, we conjugated lipid nanocarriers (NCs) with antibodies that bind cell adhesion molecules expressed at the BBB. In the transient middle cerebral artery occlusion mouse model, NCs targeted to vascular cellular adhesion molecule-1 (VCAM) achieved the highest level of brain delivery, nearly two orders of magnitude higher than untargeted ones. VCAM-targeted lipid nanoparticles with luciferase-encoding mRNA and Cre-recombinase showed selective expression in the ischemic brain. Anti-inflammatory drugs administered intravenously after ischemic stroke reduced cerebral infarct volume by 62% (interleukin-10 mRNA) or 35% (dexamethasone) only when they were encapsulated in VCAM-targeted NCs. Thus, VCAM-targeted lipid NCs represent a new platform for strongly concentrating drugs within the compromised BBB of penumbra, thereby ameliorating AIS.

Effect of Neutralizing Monoclonal Antibody Treatment on Early Trajectories of Virologic and Immunologic Biomarkers in Patients Hospitalized With COVID-19.

BACKGROUND: Neutralizing monoclonal antibodies (nmAbs) failed to show clear benefit for hospitalized patients with coronavirus disease 2019 (COVID-19). Dynamics of virologic and immunologic biomarkers remain poorly understood. METHODS: Participants enrolled in the Therapeutics for Inpatients with COVID-19 trials were randomized to nmAb versus placebo. Longitudinal differences between treatment and placebo groups in levels of plasma nucleocapsid antigen (N-Ag), anti-nucleocapsid antibody, C-reactive protein, interleukin-6, and D-dimer at enrollment, day 1, 3, and 5 were estimated using linear mixed models. A 7-point pulmonary ordinal scale assessed at day 5 was compared using proportional odds models. RESULTS: Analysis included 2149 participants enrolled between August 2020 and September 2021. Treatment resulted in 20% lower levels of plasma N-Ag compared with placebo (95% confidence interval, 12%-27%; P < .001), and a steeper rate of decline through the first 5 days (P < .001). The treatment difference did not vary between subgroups, and no difference was observed in trajectories of other biomarkers or the day 5 pulmonary ordinal scale. CONCLUSIONS: Our study suggests that nmAb has an antiviral effect assessed by plasma N-Ag among hospitalized patients with COVID-19, with no blunting of the endogenous anti-nucleocapsid antibody response. No effect on systemic inflammation or day 5 clinical status was observed. CLINICAL TRIALS REGISTRATION: NCT04501978.

Wind Shapes the Growth Strategies of Trees in a Tropical Forest.

In tropical forests, trees strategically balance growth patterns to optimise fitness amid multiple environmental stressors. Wind poses the primary risk to a tree's mechanical stability, prompting developments such as thicker trunks to withstand the bending forces. Therefore, a trade-off in resource allocation exists between diameter growth and vertical growth to compete for light. We explore this trade-off by measuring the relative wind mortality risk for 95 trees in a tropical forest in Panama and testing how it varies with tree size, species and wind exposure. Surprisingly, local wind exposure and tree size had minimal impact on wind mortality risk; instead, species wood density emerged as the crucial factor. Low wood density species exhibited a significantly greater wind mortality risk, suggesting a prioritisation of competition for light over biomechanical stability. Our study highlights the pivotal role of wind safety in shaping the life-history strategy of trees and structuring diverse tropical forests.

Astrocyte TrkB promotes brain injury and edema formation in ischemic stroke.

Following ischemic stroke astrocytes undergo rapid molecular and functional changes that may accentuate tissue damage. In this study we identified the neurotrophin receptor TrkB in astrocytes as a key promoter of acute CNS injury in ischemic stroke. In fact, TrkB protein was strongly upregulated in astrocytes after human and experimental stroke, and transgenic mice lacking astrocyte TrkB displayed significantly smaller lesion volume, lower brain atrophy and better motor performance than control animals after transient middle cerebral artery occlusion. Neuropathological studies evidenced that edema directly correlated with astrogliosis and was limited in transgenic mice. Importantly, adaptive levels of the water channel AQP4 was astrocyte TrkB-dependent as AQP4 upregulation after stroke did not occur in mice lacking astrocyte TrkB. In vitro experiments with wild-type and/or TrkB-deficient astrocytes highlighted TrkB-dependent upregulation of AQP4 via activation of HIF1-alpha under hypoxia. Collectively, our observations indicate that TrkB signaling in astrocytes contributes to the development of edema and worsens cerebral ischemia.

Variations in CD4 counts during pregnancy in women living with HIV.

OBJECTIVE: Our objective was to determine the frequency at which CD4 counts drop below 200 cells/mm3 during pregnancy in women living with HIV and to identify factors associated with this. METHODS: Data from 2005 to 2020 from two prospective Canadian cohorts of pregnant women living with HIV were extracted. As per national guidelines, women received antiretroviral therapy and CD4 counts were monitored once per trimester and at delivery. RESULTS: Among 775 included cases, 72 (9.3%) had CD4 counts <200 cells/mm3 at the first pregnancy visit. Of the 703 remaining pregnancies with CD4 counts ≥200 cells/mm3 at the initial visit, 20 (2.8%) were associated with a drop to <200 cells/mm3 . In univariate analysis, factors associated with this drop were coinfection with hepatitis B virus or hepatitis C virus (odds ratio [OR] 4.0, 95% confidence interval [CI] 1.52-10.50), lower first visit CD4 counts (OR 0.165, 95% CI 0.08-0.34), and baseline haemoglobin levels <11 g/dL (OR 2.89, 95% CI 1.04-8.00). In multivariable analysis, only CD4 count at first visit remained independently associated with this drop. A cut-off CD4 count ≤450 cells/mm3 at the first pregnancy visit had a sensitivity of 100% to detect cases of CD4 drop to <200 cells/mm3 . CONCLUSION: A drop of CD4 count to <200 cells/mm3 is uncommon during pregnancy in women living with HIV. Our results suggest that CD4 monitoring only once in pregnancy would be safe in women whose CD4 count is >450 cells/mm3 at the first pregnancy visit.

Factors associated with HIV viral load control in the early postpartum period - a Canadian prospective cohort study.

Despite success in managing HIV during pregnancy, challenges remain around sustained adherence with antiretroviral therapy (ART), and the suboptimal viral load (VL) suppression during the postpartum period. The objective of this study was to compare VL levels at delivery and during the postpartum period and assess factors associated with lack of viral suppression during the postpartum period in Canada. We combined data from two Canadian prospective cohorts, which included 286 HIV-positive women (352 pregnancies) who delivered between 2012 and 2020. Delivery VL, postpartum VL, and potential factors associated with an undetectable VL (<50 copies/mL), 2-18 weeks after delivery were assessed. To account for the correlation between multiple pregnancies from the same woman, generalized estimating equations were used to assess bivariate associations. Ninety-nine per cent of pregnant women were on ART during pregnancy compared to 93% during the postpartum period. Of those with available VL results (n = 214 pregnancies), 94% of women achieved an undetectable VL at delivery compared to 87% during the postpartum period. The postpartum period is a challenging time for ART use and VL control. Qualitative studies are needed to better understand these challenges and guide us in designing adequate interventions.

Rhenium fac-Tricarbonyl Bisimine Chalcogenide Complexes: Synthesis, Photophysical Studies, and Confocal and Time-Resolved Cell Microscopy.

We describe the preparation, characterization, and imaging studies of rhenium carbonyl complexes with a pyta (4-(2-pyridyl)-1,2,3-triazole) or tapy (1-(2-pyridyl)-1,2,3-triazole)-based heteroaromatic N∧N ligand and thiolate or selenoate X ligand. The stability and photophysical properties of the selenolate complexes are compared with parent chloride complexes and previously described analogues with benzenethiolate ligands. Two complexes were imaged in A549 cells upon excitation at 405 nm. Colocalization studies suggest a lysosomal accumulation, while one parent chloride complex was described to localize at the Golgi apparatus. Preliminary fluorescence lifetime measurements and imaging demonstrate potential for application in time-resolved microscopy techniques due to the long and variable lifetimes observed in cellular environments, including an increase in lifetime between the solution and solid state many times larger than previously reported.

Exploring Sense of Purpose and Conscientiousness as Correlates to Health and Well-Being With Indigenous and Low Socioeconomic Communities on Coast Salish Territories, Vancouver, Canada.

Research is needed to better understand factors promoting health and well-being with Indigenous Peoples and people with socioeconomic barriers in Canada, given they face multiple social determinants that are barriers to health. Individual dispositions, sense of purpose and conscientiousness, are known to predict health and well-being in broader samples. In a community-based approach, guided by Indigenous Elders with traditional ways of knowing, we aimed to determine whether these measures correlate with self-rated health and well-being among Indigenous (n = 149) and non-Indigenous (n = 151) Peoples in Vancouver, Canada. The majority of participants (mean age 49 years, and 58% male) had relatively low income (≤$15,000/year) and educational attainment (

Il faudrait davantage de recherches pour mieux comprendre les facteurs qui favorisent la santé et le bien-être des populations autochtones et des personnes confrontées à des obstacles socio-économiques au Canada. En effet, ces dernières sont confrontées à de multiples déterminants sociaux qui constituent des obstacles à la santé. Les dispositions individuelles, le sens du devoir et la prise de conscience sont connus pour prédire la santé et le bien-être dans des échantillons plus larges. Dans le cadre d'une approche communautaire, guidée par des aînés autochtones ayant des connaissances traditionnelles, nous avons cherché à déterminer si ces mesures sont en corrélation avec l'auto-évaluation de la santé et du bien-être chez les autochtones (n = 149) et les non-autochtones (n = 151) de Vancouver, au Canada. La majorité des participants (âge moyen de 49 ans et 58 % d'hommes) avaient des revenus (≤ 15 000 $/an) et un niveau d'éducation (études secondaires non terminées) relativement faibles. Les facteurs étaient valides et fiables dans tous les groupes. Les scores moyens étaient similaires entre les groupes autochtones et non autochtones, et plus faibles chez les participants ayant un revenu inférieur que chez ceux ayant un revenu supérieur. Les corrélations étaient similaires entre les groupes autochtones et non autochtones : le sens du devoir est significativement corrélé avec la santé (SF-6; 0,34 et 0,28, p < 0,001) et la satisfaction à l' égard de la vie (0,55 et 0,58, p < 0,001), et la prise de conscience est corrélée avec la santé (0,19 et 0,18, p < 0,05). Les corrélations étaient similaires entre les groupes de revenus. Lors de l'étude et de la promotion de la santé, de l'équité et du bien-être des communautés autochtones et à faible statut socio-économique, le sens du devoir et les dispositions individuelles sont des facteurs à prendre en compte au même titre que les déterminants sociaux de la santé.

Vaccination Ameliorates Cellular Inflammatory Responses in SARS-CoV-2 Breakthrough Infections.

BACKGROUND: Data on cellular immune responses in persons with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection following vaccination are limited. The evaluation of these patients with SARS-CoV-2 breakthrough infections may provide insight into how vaccinations limit the escalation of deleterious host inflammatory responses. METHODS: We conducted a prospective study of peripheral blood cellular immune responses to SARS-CoV-2 infection in 21 vaccinated patients, all with mild disease, and 97 unvaccinated patients stratified based on disease severity. RESULTS: We enrolled 118 persons (aged 50 years [SD 14.5 years], 52 women) with SARS-CoV-2 infection. Compared to unvaccinated patients, vaccinated patients with breakthrough infections had a higher percentage of antigen-presenting monocytes (HLA-DR+), mature monocytes (CD83+), functionally competent T cells (CD127+), and mature neutrophils (CD10+); and lower percentages of activated T cells (CD38+), activated neutrophils (CD64+), and immature B cells (CD127+CD19+). These differences widened with increased disease severity in unvaccinated patients. Longitudinal analysis showed that cellular activation decreased over time but persisted in unvaccinated patients with mild disease at 8-month follow-up. CONCLUSIONS: Patients with SARS-CoV-2 breakthrough infections exhibit cellular immune responses that limit the progression of inflammatory responses and suggest mechanisms by which vaccination limits disease severity. These data may have implications for developing more effective vaccines and therapies. Clinical Trials Registration. NCT04401449.

Timely Diagnosis of Incubating Syphilis Infections Using Treponema pallidum Transcription-Mediated Amplification Assay.

BACKGROUND: Syphilis is a complex, multistage, sexually transmitted infection (STI) caused by the bacterium Treponema pallidum subspecies pallidum (TP). New diagnostic tools are needed to minimize transmission. In this study, we aimed to assess the additional value of an investigational transcription-mediated amplification test for TP (TP-TMA) for routine diagnostics. METHODS: Between September 2021 and August 2022, visits by all participants of the national preexposure prophylaxis (PrEP) program at the sexual health center (SHC) in Amsterdam were included. Anal, pharyngeal, vaginal, and urine samples collected for Chlamydia trachomatis and Neisseria gonorrhoeae screening were additionally tested with the TP-TMA assay based on detection of 23S rRNA of TP. RESULTS: In total, 9974 SHC visits by 3283 participants were included. There were 191 infectious syphilis cases diagnosed: 26 (14%) primary syphilis, 54 (29%) secondary syphilis, and 111 (58%) early latent syphilis. In 79 of the 191 (41%) syphilis cases, at least 1 sample was TP-TMA-positive. For 16 participants, the positive TP-TMA result was not concordant with routine diagnostics. Of those, 2 participants were treated for syphilis within a week before the visit. Eight participants were treated for a syphilis notification at the visit or for another STI. Five participants were diagnosed with syphilis at the following visit, and 1 participant was lost to follow-up. CONCLUSIONS: By adding the TP-TMA assay to routine diagnostics, we identified 14 of 191 (7%) additional syphilis infections among participants of the national PrEP program. The TP-TMA assay is a useful diagnostic tool to increase syphilis case finding and thus limit the transmission of syphilis.

Vitamin D intakes among women living with and without HIV in Canada.

BACKGROUND: Patterns of vitamin D intake are relatively unexplored among women living with HIV, despite its importance for women's health. We compared vitamin D dietary and supplement intakes in women with HIV and population-based national controls and investigated barriers to intake. METHODS: In this case-control study, women with HIV in the Children and Women: AntiRetrovirals and Markers of Aging (CARMA) cohort were matched with Canadian Multicentre Osteoporosis Study (CaMos) controls. Participants were queried for vitamin D in dairy consumption, supplementation/dosage, and sociodemographic variables. We assessed barriers to supplementation and factors associated with dietary intake by regression modelling. RESULTS: Ninety-five women living with HIV were age-matched to 284 controls. Women with HIV had lower income and bone mineral density and were more likely to smoke, take multiple medications and be non-white. Vitamin D dietary intake was lower in women living with HIV versus controls [0.76 vs. 1.79 µg/day; adjusted odds ratio (aOR) for greater than or equal to median intake 0.29 (0.12-0.61), p = 0.002], but any supplementation was higher [62.2% vs. 44.7%; aOR = 3.44 (95% CI: 1.16-11.00), p = 0.03]. Total vitamin D intake was similar between groups. Smoking was associated with no supplementation; non-white ethnicity and low income were related to lower dietary intake. CONCLUSIONS: Women living with HIV showed lower dietary vitamin D intake but higher supplementation rates, suggesting that care providers are promoting supplementation. Women living with HIV who smoke, have low incomes and are non-white may particularly benefit from targeted efforts to improve vitamin D intake.

Treponema pallidum Strains Among Women and Men Who Have Sex With Women in Amsterdam, the Netherlands and Antwerp, Belgium Between 2014 and 2020.

ABSTRACT: The Treponema pallidum strain distribution among men who have sex with women were similar to the strain distribution men who have sex with men. The most prevalent strains and percentage of strains belonging to the Nichols lineage are similar to previous studies in Amsterdam focusing on men who have sex with men.

Estimation of time-specific intervention effects on continuously distributed time-to-event outcomes by targeted maximum likelihood estimation.

This work considers targeted maximum likelihood estimation (TMLE) of treatment effects on absolute risk and survival probabilities in classical time-to-event settings characterized by right-censoring and competing risks. TMLE is a general methodology combining flexible ensemble learning and semiparametric efficiency theory in a two-step procedure for substitution estimation of causal parameters. We specialize and extend the continuous-time TMLE methods for competing risks settings, proposing a targeting algorithm that iteratively updates cause-specific hazards to solve the efficient influence curve equation for the target parameter. As part of the work, we further detail and implement the recently proposed highly adaptive lasso estimator for continuous-time conditional hazards with L1 -penalized Poisson regression. The resulting estimation procedure benefits from relying solely on very mild nonparametric restrictions on the statistical model, thus providing a novel tool for machine-learning-based semiparametric causal inference for continuous-time time-to-event data. We apply the methods to a publicly available dataset on follicular cell lymphoma where subjects are followed over time until disease relapse or death without relapse. The data display important time-varying effects that can be captured by the highly adaptive lasso. In our simulations that are designed to imitate the data, we compare our methods to a similar approach based on random survival forests and to the discrete-time TMLE.

Ranking of average treatment effects with generalized random forests for time-to-event outcomes.

Linkage between drug claims data and clinical outcome allows a data-driven experimental approach to drug repurposing. We develop an estimation procedure based on generalized random forests for estimation of time-point specific average treatment effects in a time-to-event setting with competing risks. To handle right-censoring, we propose a two-step procedure for estimation, applying inverse probability weighting to construct time-point specific weighted outcomes as input for the generalized random forest. The generalized random forests adaptively handle covariate effects on the treatment assignment by applying a splitting rule that targets a causal parameter. Using simulated data we demonstrate that the method is effective for a causal search through a list of treatments to be ranked according to the magnitude of their effect on clinical outcome. We illustrate the method using the Danish national health registries where it is of interest to discover drugs with an unexpected protective effect against relapse of severe depression.

NONO::TFE3 fusion cutaneous epithelioid and spindle cell tumor: A case series.

The NONO::TFE3 fusion has been described in MiT family translocation renal cell carcinomas as well as extracutaneous perivascular epithelioid cell tumors (PEComas). PEComas are known to express myogenic and melanocytic markers but SOX10 and p63 positivity has never been reported. We report two primary cutaneous tumors that morphologically and molecularly fit PEComas, both harboring the NONO::TFE3 fusion, but with an unusual immunophenotype of SOX10 and p63 positivity. One case was on an 80-year-old male's finger, and the other one was on a 72-year-old female's thigh. Both were well-circumscribed multinodular dermal tumors composed of nests of monotonous epithelioid to spindled cells with pale to vacuolated cytoplasm, some of which were arranged around blood vessels. Both tumors were positive for SOX10, S100, and p63, focally positive for Melan-A, and negative for myogenic markers. There are very little data regarding the molecular findings of primary cutaneous PEComas. While the NONO::TFE3 fusion has been identified in extracutaneous PEComas, it has never been reported in primary cutaneous cases. We believe these cases represent a previously undescribed subtype of cutaneous tumor which shows some immunophenotypic expression of melanocytic markers and we named these cases NONO::TFE3 fusion cutaneous epithelioid and spindle cell tumor. Further, we raise the question of whether this tumor should fall under the rubric of PEComa because of its morphology, partial expression of melanocytic markers, and the presence of the NONO::TFE3 fusion, or whether these tumors represent a separate novel class of tumors since the immunophenotypic expression of SOX10 and p63 is unusual for PEComas.