Indeed, pulmonary artery endothelial cellscontribute to the increased secretion of leptin in IPAH patients.55 Increased leptin receptor expression has also been shown in PASMCs fromIPAH patients, and these cells are more proliferative to leptin.56 In PAH, plasma leptin levels are directly associated with BMI and lowerleptin levels, when adjusted by BMI, are associated with an increased overallmortality. This evidence concerns the gene LEP and pulmonary arterial hypertension.