ACTA2 and pulmonary arterial hypertension: To this end, Acta2-CreERT2, ROSA26R(mTmG/+) mice were induced with 4-OH-TM on P6.5, P8.5 and P10.5, and then rested until P60.5, after which they were subjected to 21 days of normoxia or hypoxia to induce pulmonary hypertension and right ventricle hypertrophy (Figures 4A–C).