OPA1 and migraine disorder: Interestingly, whilst NTG [38, 39, 41] and PACAP [40] can trigger PS when infused into patients with migraine (PACAP being another neuropeptide expressed in areas of interest in migraine, with a likely role in migraine pathophysiology [89–93] and future therapeutics [94–96]), CGRP has a lower tendency to do this [40].