MAPK1 and nonpapillary renal cell carcinoma: After that, we analyzed the protein expression levels of CDH5, MMP9 and MAPK1 in normal kidney tissues and ccRCC by CPTAC database, MMP13 for included in CPTAC database, and the protein expression levels of CDH5, MMP9 and MAPK1 were significantly higher than that in normal tissues in tumor tissues (Fig. 7B).