Data from the PIONEER-HF trial demonstrated a greater reduction in NT pro-BNP concentration from baseline and improved clinical outcomes at 4 to 8 weeks in patients randomized to the in-hospital initiation ARNI therapy arm, suggesting the benefit of routine ARNI initiation for patients with HFrEF hospitalized for acute decompensated HF.8 The gene discussed is NPPB; the disease is hydrops fetalis.