MAPK1 and pulmonary arterial hypertension: A study has also found chamber-specific growth associated with selective inactivation of p38 in neonatal mice led to marked increases in cardiomyocyte proliferation and hypertrophy, with eventual adult progression to pulmonary hypertension and right heart failure.[140] Notably, the roles of p38 pathways in inducing cardiac remodelling have also been investigated.