CAV1 and idiopathic pulmonary arterial hypertension: Importantly, lung sections from IPAH and HPAH patients revealed a similar sequence of events: (1) loss of endothelial CAV1 and endothelial cell disruption, (2) enhanced expression of CAV1 in VSMC, and (3) presence of neointima only in arteries that displayed enhanced expression of CAV1 in VSMC [30].