In bladder tumors, in accordance to the observed similarity between TGF-β variants and miR-21 gene expression alterations, treatment of the bladder cancer cell line 5637 with recombinant TGF-β induced a significant upregulation of miR-21 [67] and confirmed the correlation between TGF-β and miR-21 expression in cancer. Here, TGFB1 is linked to urinary bladder cancer.