Moreover, the results obtained on beta‐adrenergic receptors 1 and 2 expression in HFrEF are consistent with a previous report indicating that in human biopsies from HFrEF patients, ADRB2 levels do not show any HF‐related change, while a decrease in ADRB1 mRNA expression is evident only in patients with advanced NYHA class.9 The gene discussed is ADRB1; the disease is hydrops fetalis.