In colorectal cancer, KRAS-mutant tumors exhibit greater lactate production than wild-type tumors, and elevated lactate levels resulting from KRAS mutations sensitize tumor-specific cytotoxic CD8+ T cells to activation-induced cell death (AICD) by suppressing NF-κB activity, thereby reducing their infiltration into the tumor microenvironment (302). The gene discussed is CD8A; the disease is colorectal cancer.