MIEF1 and pulmonary arterial hypertension: The role of the mitochondrial fission proteins, MiD49 and MiD51 has not been studied as potential targets for cardioprotection, although they have been reported together with Drp1 to mediate mitochondrial division that is needed for vascular smooth muscle cell proliferation in pulmonary arterial hypertension (PAH) animal models,79 positioning mitochondrial fission as a therapeutic target for PAH.