GRIN2D and Anxiety: Previously, Yamamoto et al. reported a normal level of anxiety‐like behavior in GluN2D‐KO mice using the marble‐burying test and novelty‐suppressed feeding test, while Miyamoto et al. reported reduced anxiety in GluN2D‐KO mice in the EPM and light–dark box test (Miyamoto et al., 2002; Yamamoto et al., 2017).