In addition, the present study demonstrated that the inhibition of STAT3 induced by STAT3 siRNA resulted in the downregulation of the STAT3/HIF-1α pathway in HG-treated H9c2 cells, thereby mitigating HG-induced H9c2 cell injury and apoptosis, which was consistent with numerous other studies in which baseline phosphorylation and/or the activation of STAT3 levels also increased in certain in vitro studies, including in H9c2 cells subjected to a high glucose conditions (46) and the inhibition of the STAT3 signaling pathway attenuating cardiac injury in DCM (25,26). Here, STAT3 is linked to familial dilated cardiomyopathy.