PDCD1 and neoplasm: The presence and quality of the immune cell infiltrate of the tumor have been shown to be of prognostic potential for the response of different tumors to immunotherapies, regardless of tumor stage.37 However, when PD-L1 blockers are used, a selective expansion of tumor-infiltrating CD4+ and CD8+ T cells expressing both activating (inducible T cell costimulator (ICOS, CD278)) and inhibitory (Lymphocyte activation gene 3 (LAG-3) and PD-1) molecules is seen.40