TNF and neoplasm: By contrast, as IFN-γ-treated tumors contained high levels of endogenous cytokines TNF-α, IL-12p70 and IL-1β (Fig 2C,2D, 2F and 2G) and the tumor-infiltrating macrophages did not express putative M2 marker CD206 (Fig 4D), we find it likely that IFN-γ instead skewed the macrophages towards M1 phenotype [32].