PDCD1 and Lynch syndrome: In addition, recent data seem to suggest that both sporadic MSI-H and Lynch Syndrome-related colorectal cancer could share some therapeutically important biomarkers, such as significantly higher Thymidylate Synthase (TS) expression (potentially explaining the supposed reduced clinical benefit from 5-Fluorouracil), higher Programmed cell death-1 (PD-1)-positive tumor infiltrating lymphocytes (TIL), BRCA1/2 and CTNNB1 mutations.