Over the last 10 years, new HF drugs have merged targeting various pathways, such as those that simultaneously suppress the renin–angiotensin–aldosterone system and the breakdown of endogenous natriuretic peptides (e.g., sacubitril/valsartan), and those that inhibit the If channel and, thus, reduce heart rate (e.g., ivabradine). The gene discussed is REN; the disease is hydrops fetalis.