Hypoxia-treated p16fl/fl mice exhibited accumulation of αSMA-positive cells to distal PAs (Figures 2A,B), upregulated αSMA mRNA expression (Figure 2F), increased right ventricular hypertrophy evaluated by a Fulton's index (36) (Figure 2C), and raised RVSP (Figure 2D) compared with those treated with normoxia. Here, ACTA1 is linked to Right ventricular hypertrophy.