MS4A1 and Anxiety: Moreover, Ms4a1 knockout mice were overtly indistinguishable from wildtype mice in other ways—they exhibited similar locomotive behaviors and behaved similarly to wildtype mice in assays of anxiety (such as the elevated plus maze) (Fig. S3D and E), strongly suggesting that the failure to respond to 2,5-DMP was a specific defect in this particular odor-driven behavior and not a sign of more general nervous system dysfunction.