Indeed, addition of recombinant inhibin α into the CM from miR-218-overexpressing cells reversed the activation of SMAD2/3 phosphorylation in recipient cancer cells (Fig. 4f), whereas adding neutralizing antibody against inhibin α into the CM to treat MC3T3 cells led to de-repression of SMAD2/3 signaling (Fig. 4g). Here, SMAD2 is linked to cancer.