Treatment of RCC cell lines with recombinant TGFβ (rTGFβ) leads to the downregulation of cadherin 1 and claudin 1 (epithelial markers), and the upregulation of vimentin, ZEB1 and zinc-finger transcription factor Snai1 (mesenchymal markers) in a TGFβ/Smad-dependent manner, highlighting the contribution to EMT formation. The gene discussed is TGFB1; the disease is renal cell carcinoma.