From a series of experiments in which CTLs were treated with 20 mM lactic acid, HCl, or sodium lactate, besides an inhibitor of MCT1 (α-cyano-4-hydroxy-cinnamic acid) or lactic acid derived from melanoma cells, the authors concluded that high lactic acid concentrations in the tumor environment block the export of lactic acid by T cells, thereby disturbing their metabolism and function (60). This evidence concerns the gene SLC16A1 and neoplasm.