VIP and migraine disorder: The rest of the seven completed trials referred to pulmonary arterial hypertension, chronic obstructive pulmonary disease, migraine, and neurological disorders, etc. Similarly, 10 clinical trials involving PACAP-27/PACAP-38/VIP have been completed, out of which nine were associated with migraine while one involved nephrotic syndrome (https://clinicaltrials.gov/ct2/home (accessed on 3 December 2021)).