TAMs are heterogeneous and express pro-inflammatory M1 macrophages that are positive for CD68, CD80, inducible nitric oxide synthase (iNOS) and TNF-α, or anti-inflammatory/pro-tumoral M2 macrophages that are positive for CD163, CD206 and Arg1 markers, or both – depending upon type, stage and immune composition of a tumor (Sainz et al., 2016). The gene discussed is NOS2; the disease is neoplasm.