In session 1, the number of entries into the center zone, and the percentage of time spent in the center zone, were lower in saline-treated CD157 KO mice than in saline-treated WT mice (number of entries, t = 2.449, P < 0.05; percentage of time spent, t = 2.770, P < 0.05; Figures 3A,B), confirming the anxiety-like behavior in CD157 KO mice described previously (Lopatina et al., 2014). The gene discussed is BST1; the disease is Anxiety.