Calcitonin gene-related peptide (CGRP), specifically the alpha (α) isoform of CGRP. CGRP is a potent neuropeptide that is widely expressed in the peripheral and central nervous systems. It plays a crucial role in the pathophysiology of migraine. During a migraine attack, CGRP is released from activated trigeminal sensory nerves. It then causes vasodilation of cranial blood vessels, transmits pain signals, and promotes neurogenic inflammation in the meninges. CGRP binds to a complex receptor consisting of the calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1).