The 2021 European heart failure (HF) guidelines recommend the combination of four drugs as a standard therapy (angiotensin‐converting enzyme inhibitor [ACEI]/angiotensin receptor blocker [ARB]/angiotensin receptor‐neprilysin inhibitor [ARNI]; beta‐blocker (BB); mineralocorticoid receptor antagonist [MRA]; sodium‐glucose co‐transporter 2 inhibitor [SGLT2i]) in patients with heart failure and reduced ejection fraction (HFrEF). The gene discussed is NR3C2; the disease is hydrops fetalis.