Although galanin was not listed in the top identified genes in terms of significance (P = 0.018), it was selected as a gene of interest since this peptide has been known to regulate a variety of behavioral processes, including food intake, sexual behavior, learning, memory, reward, cognition, sleep, seizure, as well as emotion/mood-related behaviors, such as stress, fear, anxiety and depression [45]–[47]. The gene discussed is GAL; the disease is major depressive disorder.