CTLA4 and melanoma: TRM from healthy organs (brain, gut, lung, and skin) or localized in tumors (NSCLC, melanoma, etc.)express higher amounts of inhibitory receptors (PD-1, Tim-3, CTLA-4, NKG2A, BTLA, LAG-3, SPRY1, adenosine receptor A2AR, CD39, CD101, and 2B4) and costimulatory molecules (CD27, ICOS, SIRPG, and CD137) than peripheral memory CD8+ T cells or CD8+CD103neg TIL (5, 13, 20, 34, 37).