COL4A4 and nonpapillary renal cell carcinoma: The results showed that the two subtypes had frequent CNVs in the region containing oncogenes, tumor suppressor genes (e.g., VHL and PBRM1) and metabolism regulator (e.g., COL4A3 and COL4A4), indicating that CNVs might play a significant role in the tumorigenesis and progression of ccRCC.