FOXB1 and Anxiety: Here we show that major neuropathological and behavioral traits of St8sia2−/− mice can be dissected and recapitulated by cKO of St8sia2. The di- and mesencephalic ablation of St8sia2 driven by Foxb1-Cre causes compromised MB connectivity and segregates hyperactivity in the open field, deficits of sensorimotor gating, and reduced anxiety in the elevated plus maze from other psychotic and cognitive symptoms of St8sia2 knockout mice.