GREM2 and Anxiety: In both the acute and chronic restraint stress paradigms, Grem2−/− mice spent significantly more total (data not shown) or percentage of time in the closed arms than WT counterparts, suggesting higher levels of anxiety (Fig. 4C–H; acute, WT, 70.65% ± 2.19%; n = 17; Grem2−/−, 78.48% ± 1.63%; n = 15; p = 0.0087u/chronic, WT, 86.52% ± 2.01%; n = 17; Grem2−/−, 91.21% ± 1.678%; n = 15; p = 0.0302v).