TGFB1 and nonpapillary renal cell carcinoma: To study the reversibility of the mesenchymal transition, 5 ccRCC and 1 pRCC cell line were treated with TGF-β1, re-cultured in medium in the absence of TGF-β1 and subsequently analyzed for EMT markers at the mRNA level (Figure 6B, Supplementary Figure 3).