Between haemodynamic and clinical pulmonary congestion (Fig. 2), an intermediate stage in the presymptomatic phase, detectable at lung auscultation or more often by lung ultrasound (US) (US-B lines) of chest X-ray Kerley B lines (Fig. 1) or an increase in levels of brain natriuretic peptide (BNP), which may act as indicators and intermediate endpoints of frank pulmonary oedema. The gene discussed is NPPB; the disease is pulmonary edema.