ACE inhibitors: angiotensin-converting enzyme inhibitors, ARBs: angiotensin receptor blockers, CS: cardiac sarcoidosis, FDG-PET: fluorodeoxyglucose positron emission tomography, HF: heart failure, HTx: heart transplantation, ICD: implantable cardioverter-defibrillator, LVEF: left ventricular ejection fraction, LVAD: left ventricular assist device, RCM: restrictive cardiomyopathy, SCD: sudden cardiac death, SGLT-2 inhibitors: sodium-glucose cotransporter-2 inhibitors, TNF-α: tumor necrosis factor-alpha, VT: ventricular tachycardia, MRI: magnetic resonance imaging. The gene discussed is TNF; the disease is hydrops fetalis.