This gene, DPP6, has been proven as a candidate gene for amyotrophic lateral sclerosis (ALS) in the patients with ALS against the non-ALS population [41,42,43] and could also be a potential factor that led to mental diseases, such as autism [44] and posttraumatic stress disorder (PTSD) [45]. Here, DPP6 is linked to post-traumatic stress disorder.