PDCD1 and colorectal carcinoma: We first explored, using flow cytometry, the ex vivo expression of five key inhibitory ICs by CD3+ TILs from CRC-dissociated tumors (n = 40) and showed that the vast majority (more than 80%) of these cells expressed not only PD-1 but also TIGIT (also reflected by a high MFI) and, at a lower frequency, Tim-3, Lag3, and then, NKG2A.