HAVCR2 and neoplasm: Despite the deficiency of self-renewal capacity or polyfunctionality in terminally exhausted T cells, of which TIM-3 is characteristic,16 19 20 23 it is this population that retains cytotoxicity and is responsible for tumor control.23 Therefore, it is possible that removing TIM-3 or blocking its ligand interactions in TIM-3hi exhausted Ptpn22KO TILs depletes those remaining cells with limited but enduring cytotoxic potential, thereby further impairing their antitumor response.