PDPN and Anxiety: Our experimental results indicated, for the first time, that Pdpn deletion associates with an apparent preference for avoiding the brightly lit center of an open space in the OF test (Figure 3A), which is a behavior indicative of increased anxiety (Olivier et al., 2008; Bailey and Crawley, 2009; Hughes et al., 2014; Kulesskaya and Voikar, 2014; Sturman et al., 2018).