IFNG and neoplasm: Classically activated M1 macrophages are induced by pro-inflammatory stimuli such as interferon gamma (IFNγ), tumour necrosis factor alpha (TNFα) or lipopolysaccharide exposure; and combat pathogens and tumour cells via the production of reactive oxygen species and inducing Th1 responses via interleukins IL-12 and IL-23 production (61).