ADCYAP1 and migraine disorder: Therefore, PACAP antagonism has been clearly identified as a novel therapeutic target, and therefore, specifically considering preliminary provocation studies showing that the infusion of PACAP, but not of VIP, was able to induce migraine-like attacks, the attention was primarily focused on PAC-1 receptor (characterized by an extremely higher affinity for the PACAP compared to the VIP unlike the VPAC1 and VPAC2 receptors) [45].