AKT1 and idiopathic pulmonary arterial hypertension: In PAECs from IPAH patients and PH animal models, increased Ca2+ influx results in Ca2+-dependent phosphorylation of Akt and ERK, which subsequently upregulates the expression of Notch ligands Jagged1/2 and DLL4, contributing to pulmonary vascular remodeling associated with PAH and PH.373