CD274 and neoplasm: Indeed, Taube et al. described increased expression of PD-L1 in melanoma cells immediately adjacent to TILs while tumors with minimal TIL infiltration were less likely to express PD-L1, suggesting that tumor cells protects themselves against immune-mediated destruction, at least partially, by inactivating effector T cells through PD-1/PD-L1 engagement [63].