SMAD3 and nonpapillary renal cell carcinoma: Next, we found that depletion of PIM1 remarkably decreased the phosphorylation of both Smad2 and Smad3 in ccRCC cell nuclei without significantly changing the total Smad2 and Smad3 protein levels, suggesting that PIM1 regulates Smads via interactions with Smad2 or Smad3 in the nucleus and that the subsequent phosphorylation of Smad2 and Smad3 induces EMT.