The expression of CX3CL1 is associated with its DNA methylation level in ccRCC.195 Decreased expression of succinate dehydrogenase (SDH), which is responsible for oxidative phosphorylation (OXPHOS) and flux through the tricarboxylic acid (TCA) cycle, is correlated with ccRCC progression. This evidence concerns the gene CX3CL1 and nonpapillary renal cell carcinoma.