In addition, research has shown that after infection, the promoter of the arginine vasopressin (AVP) gene in the host is hypomethylated, leading to increased AVP expression, increased testosterone secretion (Figure 2C), and ultimately reduces fear of cat urine odor in infected rats, which may be linked to the exhibition of suicidal behaviors (Hari Dass and Vyas, 2014). The gene discussed is AVP; the disease is infection.