Tumor-derived lactate is taken up by GAMs through their monocarboxylate transporters (MCT1, MCT2 and MCT4), leading to the transcription of the vascular endothelial growth factor (VEGF) and the l-arginine- metabolizing enzyme arginase-1 (ARG1) genes inhibiting T-cell activation and proliferation [11]. Here, ARG1 is linked to neoplasm.