CA2 and idiopathic pulmonary arterial hypertension: Dihydropyridine Ca2+ channel blockers, such as nifedipine, exacerbate mPAP in IPAH patients by potentiating CaSR activity in PASMCs, independent of their effects on Ca2+ channels.483 This suggests that targeting CaSR could potentially provide a more effective therapeutic strategy by avoiding the adverse effects of these blockers in IPAH patients, who often have upregulated CaSR activity.