SMAD3 and neoplasm: Our results showing TR4 might function as suppressor through modulation of miR-373-3p to alter the expression of TGFβR2/p-Smad3 to increase the PCa metastasis, therefore represents the 3rd molecule (in addition to miR-373-3p and TGFβ) in this newly identified pathway that has both suppressor and stimulator roles to influence the tumor metastasis.