Increased ET‐1 production can trigger an inflammatory cascade, raising the plasma levels of pro‐inflammatory cytokines in patients with pulmonary arterial hypertension.40 ET‐1 is over‐expressed in both early‐ and late‐stage SSc, as shown by the elevated levels found in the blood vessels, lungs, kidneys and skin of SSc patients.41 Adhesion molecules as E‐selectin, sICAM‐1 (intercellular adhesion molecule 1) and sVCAM‐1 (vascular cell adhesion molecule 1) are significantly elevated in SSc patients. This evidence concerns the gene EDN1 and systemic sclerosis.