Moreover, some recent studies show that circular RNAs, such as circCACTIN and circCCDC66, also affect cancer progression by regulating the TGF-β pathway [68,69], and circular RNA cESRP1 can increase the chemosensitivity of cancer cells by inducing Smad7 and blocking the TGF-β pathway [70]. Here, TGFB1 is linked to cancer.