A higher number of CD3+ and CD8+ TILs and increased PD1 expression (but not PDL1) are observed in the hypermutated subgroups (POLE mutations or MSI-H/dMMR) of endometrial cancer than in the hypomutated microsatellite-stable subgroup [305], explaining why MSI-H/dMMR-positive endometrial cancer is sensitive to PD1 blockade. This evidence concerns the gene CD274 and endometrial cancer.