Interestingly, in ccRCC, methionine can be supplied by a subpopulation of pericytes expressing platelet-derived growth factor receptor-beta (PDGFR-β) and G-protein-coupled receptor 91 (GPR91), which are activated by succinate secreted by the TICs and received by GPR91 on pericytes [179]. This evidence concerns the gene SUCNR1 and nonpapillary renal cell carcinoma.