SELP and chronic thromboembolic pulmonary hypertension: P-selectin is the most studied platelet activation receptor and its elevation on the platelet surface and also its release into the circulation has been shown for several diseases with a thrombotic or inflammatory background such as acute venous thromboembolism, coronary artery disease, stroke, chronic thromboembolic pulmonary hypertension, infectious respiratory diseases and metabolic syndrome [20–25].