Additionally, we also observed higher number of cyclin A (S-phase), and phospho-Aurora kinases and phospho-Histone 3 (G2/M-phase) positive CMs nuclei in the hypertrophied RVs as compared to control RVs, suggesting that the CMs could be proliferating in the PAH-induced hypertrophied RVs. The gene discussed is CCNA2; the disease is pulmonary arterial hypertension.