SMAD3 and urinary bladder carcinoma: Although several ceRNA pairs have been reported to regulate the EMT process in bladder cancer, the present study may shed light on the fact that the LINC02470–miR-143-3p–SMAD3 axis forms feedback loops with TGF-β at different tumor stages, resulting in dual functions, which may help to explain the “TGF-β paradox”, i.e., the dichotomous nature of TGF-β during tumorigenesis.