Moreover, in an animal model of medication-overuse headache induced by repeated administration of sumatriptan [17]: (i) increases in serum PRL levels were observed only in females; (ii) co-administration of sumatriptan plus cabergoline prevents allodynia and downregulation of the short isoform of PRLR, which is involved in nociception; and (iii) PRLR co-localizes with the 5-HT receptors (i.e. 5-HT1B/1D receptors, the main therapeutic targets for triptans in the acute treatment for migraine) [17]. The gene discussed is PRLR; the disease is migraine disorder.