CD274 and neoplasm: Here, PD-L1 makes a very strong contribution to immune evasion by causing reduced IL-2 production, cell cycle arrest, and promotion of exhaustion in immune effector cells after binding to its receptor PD-1, for example, on tumor-infiltrating lymphocytes (TILs, e.g., CD8+ cytotoxic T lymphocytes (CTLs)) [7,8].