REN and hydrops fetalis: Despite rigorous glycemic control, symptomatic lipid-lowering drugs, ion-channel blockers, and common use of renin–angiotensin–aldosterone system (RAAS) inhibitors, the prevalence of HF progression has remained steady, a fact that emphasizes the need for better therapies to stop HF progression (Domanski et al., 2003; Granger et al., 2003; Klotz et al., 2007).