HAP1 and major depressive disorder: To rule out the possibility that our Hap1 KO mice had any physical impairment that might result in poor performances in depression tests, as well as a locomotor activity assay, we did a rotarod test on both P1 KO and camk2a-Hap1 KO mice; we found no such impairment in either of the KO groups (S2A Fig).