Moreover, it has been reported that the increase of the ceramide/S1P ratio can impair the expression of specific G protein-coupled receptors (S1P receptors, S1PRs) on which S1P acts as a ligand and, more interestingly, can exert a powerful antitumor activity in melanoma cells showing resistance to BRAFi 153. The gene discussed is MBTPS1; the disease is melanoma.