Many methods have been used to assess the ANS function of patients with migraine, including heart rate variability analysis (Bugdayci et al., 2010), pupillary light reflex (Mylius et al., 2003; Matei et al., 2015; Mamontov et al., 2016), analysis of salivary α-amylase level (Cambron et al., 2014), and the detection of vasoactive intestinal peptide (VIP) (Torun et al., 2013). The gene discussed is VIP; the disease is migraine disorder.