PPARA and melanoma: In concordance, it has been reported that PPAR-γ inhibition increases the efficiency of anti-PD-1 antibody immunotherapy, leading to the suppression of tumor progression in colon adenocarcinoma and melanoma models [20,21]; likewise, an agonist for another isomer, PPARα, is able to restore the anti-melanoma effects of tumor-infiltrating lymphocytes (TILs) by blocking the reprogramming to fatty acid catabolism in mice [22].