A small cohort study of SSc patients revealed increased serum levels of ICAM-1, platelet endothelial cell adhesion molecule-1, P-selectin, and VCAM-1 compared with healthy controls at baseline, all of which returned to normal levels following 12 months of treatment with bosentan, a dual antagonist of endothelin-1 for the endothelin-1 type A and type B receptors [110]. Here, SELP is linked to systemic sclerosis.