In this context, evidence suggests that the balance of sex hormones plays a central role in infections, because progesterone favors the regulation of the immunological response and protection against infectious diseases [10, 11] by reducing inflammatory cytokines, IL-6 and TNF, and restoring the antioxidant defense system, whereas testosterone contributes to the reduction of the immune response, facilitating the development of infections, as has been demonstrated in orchiectomized animals that were more resistant to this type of infection [12]. The gene discussed is TNF; the disease is infection.