To investigate the molecular mechanism underlying EMT in ccRCC cells, immunoblotting assays were performed to quantify the expression levels of Smad2, Smad3, p-Smad2 and p-Smad3 in both ACHN and 786-O cells transfected with PIM1shRNA or control-shRNA. The gene discussed is SMAD3; the disease is nonpapillary renal cell carcinoma.