These behaviors suggest that CXCL12 mimics the increase in anxiety induced by prenatal HFD exposure, an effect correlated with maternal obesity and HFD exposure (Bilbo and Tsang, 2010; Sullivan et al., 2010) and possibly attributed to the increase in ENK levels in the PVN. The gene discussed is CXCL12; the disease is obesity due to melanocortin 4 receptor deficiency.