Male and female mice were similar in both control and EC-Atm-/- mice under normoxia and showed comparable pulmonary hypertension following hypoxia as judged by right ventricular systolic pressure, right ventricular hypertrophy (Fig. 3a, b) and pulmonary artery acceleration time/ejection time (PAAT/ET) (Supplementary Fig. 3c, d). The gene discussed is ATM; the disease is pulmonary hypertension.