ADCYAP1 and migraine disorder: The failure of efficacy in the non-responders to current medications suggests that CGRP is not the only cause of migraine and that other neuropeptides are involved; e.g., pituitary adenylate cyclase-activating peptide (PACAP-38) works independently of CGRP or 5-HT1B/1D/1F receptors (Kuburas et al., 2021; Ernstsen et al., 2022).