LDHA-associated lactate production and acidification diminish the levels of nuclear factor of activated T cells and T and NK cell activation, leading to immune evasion.3 Meanwhile, high level of lactate also promotes PD-1 expression in regulatory T cells to sustain its immunosuppressive function.4 Mechanically, this work found tumor-derived lactate as an inhibitor of CD8+ T cell cytotoxicity, inducing a switch of pyruvate utilization from PC to PDH and altering T cell metabolic reprogramming. The gene discussed is CD8A; the disease is neoplasm.