SMAD2 and prostate cancer: However PMEPA1 accelerates NEDD‐meditated derogation of androgen and inhibits the androgen receptor signalling, moreover, PMEPA1 inhibits the prostate cancer cell proliferation.11, 34 PMEPA1 also suppresses prostate cancer metastases to bone by inhibition of TGF‐β signalling and interfering the formation of complex of Smad2/3 and Smad4.13 In this study, the experiments data in vivo and in vitro showed PMEPA1 promoted migration and invasion as a pro‐metastatic molecule.