Aged 18-65 y with a 12-mo history of migraine, no previous SARS-CoV-2 infection, no contraindication or recent prescription of CGRP mAb (>5 mo), no prior use of CGRP receptor antagonists (rimegepant, ubrogepant, or atogepant), regular health care system contact, potential follow-up, not residing in long-term care facilities, and baseline defined as the first eligibility month. The gene discussed is CALCA; the disease is migraine disorder.