Sodium chloride (high-salt diet, HSD) exhibits context-dependent modulation of the axis: HSD suppresses MDSC function via p38/MAPK-NFAT5 signaling, expanding cytotoxic NK cells and enhancing CD8+ T cell effector function (IFN-γ, granzyme B) to boost anti-PD-1 efficacy in melanoma and CRC models (311, 312). This evidence concerns the gene CD8A and melanoma.