CALCA and migraine disorder: This notion is based on the observation that infusion of CGRP in migraineurs can trigger a migraine attack [1, 2] and, more importantly, inhibition of the CGRP system has been proven beneficial in migraine patients, whereby different ways of interfering with the CGRP system appear to be effective: Inhibition of CGRP release by triptans, CGRP receptor inhibition by gepants and scavenging CGRP or blocking its receptor by monoclonal antibodies.