CTLA4 and neoplasm: In addition to PD-1, PD-L1, and CTLA-4, other inhibitory receptors—including T cell immunoglobulin and mucin-domain containing-3 (TIM-3) and lymphocyte activation gene-3 (LAG-3)—are increasingly recognized as markers and mediators of T-cell dysfunction within the tumor microenvironment [26,27,28].