NRG1 and hydrops fetalis: In cases of heart failure, NRG1/ErbB signaling is significantly impaired (Galindo et al., 2014; Gupte et al., 2017), and administration of NRG1 attenuates the progression of HF, inhibits myocardial fibrosis and apoptosis, and reduces oxidant-producing enzymes (Gupte et al., 2017).