Furthermore, CD3+ and CD8+ TIL cell counts are much higher in POLE ultra-mutated and MSI hyper-mutated tumors, with a higher tumor antigen load and an upregulation in PD-1 and PD-L1 expressions: a related strengthened immune activation could be responsible for their better prognosis compared to microsatellite stable EC (159, 160). This evidence concerns the gene CD8A and neoplasm.