HMOX1 and Duchenne muscular dystrophy: In the next step, we thus evaluated the levels of NRF2, a protein involved in heme metabolism, and HO-1, an antioxidant enzyme, which catalyses the degradation of heme to biliverdin, carbon monoxide, and ferrous iron.34 HO-1 is a direct target of NRF2, and both proteins are inextricably linked to iron homeostasis.34 Interestingly, both NRF2 and HO-1 were found to be up-regulated in DMD hiPSC-CM, including patient-specific cardiomyocytes in which gene correction reversed the level of both proteins.