Animals exposed to predator odor show a wide range of impacts, including a long-term increase in anxiety behaviors, changes in activity levels, increased levels of circulating glucocorticoids (GCs), decreased body weight and altered transcript abundance of brain-derived neurotrophic factor (BDNF; Adamec et al., 2004; Zoladz et al., 2008; Bazak et al., 2009). The gene discussed is BDNF; the disease is Anxiety.