TNF and cancer: M1-like macrophages are formed in response to IFN-γ, TNF, granulocyte–macrophage colony-stimulating factor (GM-CSF) and various pathogen-derived signals (primarily, lipopolysaccharide (LPS)); the cells produce elevated levels of pro-inflammatory factors, such as TNF, IL-1β and IL-12, implement effective antigen presentation and costimulation, as well as mediate protective anti-infectious and anti-cancer responses.