Although plasma renin activity and aldosterone levels showed no significant differences between one renin and two renin gene mice, C57Bl/6, C3H, and BALB/c mouse strains, which do not harbor the second renin gene (Ren-2), are preferential for translationally relevant experimental DCM-HF studies as they more closely represent the human condition [81,189,190]. Here, REN is linked to hydrops fetalis.