Although the RCC cell lines showed a low expression of the TGFBR2 after treatment with recombinant TGF-β1, we detected the induction of the Smad-dependent pathway by high levels of the phosphorylated Smad2 protein (pSmad2) and the downstream target MMP2 in comparison to untreated RCC cells (Figure 2B, 2C). This evidence concerns the gene SMAD2 and renal cell carcinoma.