NRG1 administration improves cardiac dysfunction and reduces mortality in several models of LV (left ventricular) failure (Liu et al., 2006), and clinical trials have demonstrated the efficacy and safety of NRG1 in improving LV function in patients with HF (Gao et al., 2010; Jabbour et al., 2011a). This evidence concerns the gene NRG1 and hydrops fetalis.