It is worth mentioning that most previous studies only evaluated the difference of prolactin level among migraineurs and a headache‐free control group (Cavestro et al., 2006; Guldiken et al., 2011; Li et al., 2018; Masoud & Fakharian, 2005; Seddighi & Dehghani, 2002; Taha & Mohammed, 2019; Vega et al., 2017), while in our study, we compared prolactin levels in patients with chronic migraine, episodic migraine in ictal and interictal phases and control subjects separately. The gene discussed is PRL; the disease is Headache.