We first examined Pdpn+/+ and Pdpn−/− mice in the OFT and observed that Pdpn−/− mice showed significantly higher anxiety-like levels compared to their wild type littermates as indicated by a reduction in percentage of the time that Pdpn−/− mice spent in the center of the Open field arena (Figure 3A, left panel). The gene discussed is PDPN; the disease is Anxiety.