Several studies show that PACAP plays important roles in numerous pathological conditions such as tumor growth and proliferation (D’Amico et al. 2021b, c; Maugeri et al. 2018a, 2021; Moody et al. 2016) and nervous system disorders (Moody and Jensen 2021) like migraine, schizophrenia, anxiety, and depression (Eslami et al. 2021; Kormos et al. 2016; Martelle et al. 2021; Ross et al. 2020; Tiihonen et al. 2021) as well as inflammatory conditions (Moody and Jensen 2021; Tamas et al. 2021), sudden infant death syndrome (Shi et al. 2021), and hearing loss (Fulop et al. 2019; Ruel et al. 2021). The gene discussed is ADCYAP1; the disease is migraine disorder.