EDN1 and migraine disorder: This is supported by the evidence of vasodilatory reduction and contextual increase of vasoconstrictive substances during the attacks (namely ET-1, metalloproteinase 9, soluble intercellular adhesion molecules) [36], as well as lower levels of endothelium self-repairing progenitor cells (EPCs) and higher ET-1 levels in migraine subjects compared to healthy controls [37].