ATM and Right ventricular hypertrophy: 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).