Therefore, we studied the effect of TGF-β1 treatment on growth properties, phenotype, and gene expression pattern in the two most common RCC subtypes ccRCC and pRCC by characterization of their ability to transition from an epithelial to a mesenchymal cell type using microscopy, flow cytometry, qRT-PCR and Western blot analysis, respectively. The gene discussed is TGFB1; the disease is renal cell carcinoma.