HGF and nonpapillary renal cell carcinoma: Previous studies have proved the several classical signaling mechanisms were involved in promoting ccRCC, such as VHL/HIF1α 40, PI3K/Akt/mTOR 41, HGF/MET 42, MAPK 43, and Wnt/β-Catenin 44, etc. TRPV1 expression was discovered to be negatively correlated with expression of the key proteins in those pathways and positively correlated to cancer inhibiting genes, p53 and VHL.