In migraine, only cerebral vessel and ipsilateral jugular vein levels, but not plasma levels, of CGRP are elevated (Goadsby et al., 1990; Edvinsson and Goadsby, 1995; Ashina et al., 2000; Cernuda-Morollón et al., 2015; Messlinger, 2018). This evidence concerns the gene CALCA and migraine disorder.