NRGN and attention deficit-hyperactivity disorder: Until recently, Nrgn KO mice have been suggested to be an animal model of schizophrenia and Jacobsen's syndrome with ADHD symptoms,15 as these mice show hyperactivity,15 altered anxiety‐like behavior,16 decreased sociability,15 impaired reference memory,15, 16, 17 and impaired sensorimotor gating.18