According to the TCGA database, in the primary RCC tumor samples TGFβ1 so far was analyzed in 71 patients (1 mutation was detected), TGFβ2 in 167 cases (1 mutation), TGFβ3 in 263 cases (1 mutation), TGFβRI in 154 cases (1 mutation), TGFβRII in 536 cases (1 mutation), Smad1 in 117 cases (2 mutations), Smad2 in 168 cases (4 mutations), Smad3 in 77 cases (1 mutations), Smad4 in 166 cases (1 mutations), Smad5 in 340 cases, Smad6 in 78 cases (1 mutation), Smad7 in 165 cases (2 mutations), Smad9 in 164 cases (2 mutations were detected). This evidence concerns the gene SMAD6 and renal cell carcinoma.