TNF and infection: Depending on the type of pathogens (pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs)) and an environment rich in IFN-γ, the infection or tissue injury promotes the classic activation of highly proinflammatory type 1 M1 macrophages, expressing high levels of nitric oxide synthase (NOS2), interleukin- (IL-) 1β, and tumor necrosis factor (TNF), aimed at the destruction of the pathogens [8].