CD274 and colorectal carcinoma: dMMR/MSI-H CRC patients with a higher PD-L1 level had a deeper functional suppression of TILs than those pMMR/MSI-L CRC patients with a lower PD-L1 level, and blocking PD-1/PD-L1 might relieve such suppression and reactivate the function of TILs (61, 62).