GFAP levels were significantly increased in migraine patients (median 103.15 pg/mL [IQR 70.98–146.34] vs. 69.43 pg/mL [IQR 53.04–91.85], p < 0.001), particularly in those with medication overuse (106.08 [IQR 87.94–159.07] vs. 71.38 [IQR 54.16–135.06], p = 0.007), without difference between EM and CM (p = 0.985). The gene discussed is GFAP; the disease is migraine disorder.