DRD2 and post-traumatic stress disorder: Among those, we observed genes that have been associated with PTSD in previous human studies (e.g., DRD2 and HTR2a) (26–29) or linked to anxiety or PTSD-like behaviors in humans or animal models (Igf2, Grm2, Clock, Trhr) (30–32) (Table S5; Figure 3).