CD8A and neoplasm: Recently, an interesting study published in Cell Metabolism discovered a novel metabolic interaction between tumors and T cells, identifying that tumor-derived lactate inhibited CD8+ T cell cytotoxicity by inducing a switch of pyruvate utilization from pyruvate carboxylase (PC) to pyruvate dehydrogenase (PDH), and PDH inhibition facilitated PC activity and T cell cytotoxicity through increasing succinate secretion, in turn leading to synergistic effects on tumor therapy with immunotherapy, which provides a promising model for tumor treatment targeting T cell metabolism.1