In the acute phase of infection, M1 macrophages play an inflammatory role, stimulating the expression of molecules such as iNOS, NADPH, NO, and ROS, and increasing the expression of MHC class II, CD86, AP-1, and NF-κB. They also produce cytokines such as TNF-α, IL-6, IL-12, and IL-1β [29,30,31]. The gene discussed is NOS2; the disease is infection.