Additional layers of regulation include miR-34b, which modulates TGF-β signalling components and suppresses proliferation, migration and invasion in prostate cancer cells when upregulated [33], and the Int7G24A intronic variant of TGFBR1, which has been associated with increased susceptibility to bladder transitional cell carcinoma and RCC [34]. Here, TGFB1 is linked to renal cell carcinoma.