What is more, evidence from a study of patients with systemic sclerosis and PAH proved that a regimen of bosentan for 12 months could normalize the expression of ICAM-1, VCAM-1, P-selectin, and platelet/endothelial cell adhesion molecule (PECAM-1) and restore T-cell function [257]. The gene discussed is ICAM1; the disease is pulmonary arterial hypertension.