CTLA4 and cancer: In 2020, Ye et al. performed a pan-cancer analysis that reported heterogeneity in molecular biomarkers between the sexes, including tumor mutation burden (TMB), individual gene mutation (PBRM1, BRCA2), T cell-inflamed gene expression profile (GEP), neoantigen load, cytolytic activity (CYT) and protein expression of checkpoints (CTLA-4, PD-L1, PD-L2).