As expected, TGF‐β1 and SMAD3 are among those altered metastasis‐related genes (Table S1B) whose expression was increased in RCC cells when ERβ expression was elevated (A498: ERβ vs. vector, P < 0.01) and decreased in RCC cells when ERβ was knocked down (786‐O: shERβ vs. vector, P < 0.01). This evidence concerns the gene TGFB1 and renal cell carcinoma.