TGFB1 and papillary renal cell carcinoma: Importantly, TGF-β1, as the most common isoform in human cancers (reference PMID: 32710082), is upregulated in renal cancer, head and neck cancer, stomach cancer, etc. To study the functional importance of TGF-β1 in patients with renal cell carcinoma, we analyzed the online database (https://kmplot.com/analysis/) and found that the mRNA expression of TGF-β1 is negatively correlated to the ten-year overall survival of patients in both clear cell renal cell carcinoma and papillary renal cell carcinoma (Figure 1(a,b)).