Interestingly, we also identified many metabolic pathways like PPAR signaling pathway, and Glycine serine and threonine metabolism pathways were significantly enriched with down-regulated genes, which may suggest the metabolic abnormalities in UTUC as observed in clear cell renal cell carcinoma (ccRCC) [9, 13]. This evidence concerns the gene PPARA and nonpapillary renal cell carcinoma.