Another two bulk RNA-seq datasets, comparing mRNA expression between human ccRCC and normal kidney tissue, also revealed pro-fibrosis signatures ACTA2 (α-SMA), COL1A1, COL23A1, VEGFA, and TGFB1 as the top differentially expressed genes (DEGs) upregulated in ccRCC (Xiong et al., 2014; Eikrem et al., 2016). Here, COL1A1 is linked to nonpapillary renal cell carcinoma.