M2 macrophage subpopulation represents the main type of TAM and is involved in tumor development and progression; production of anti-inflammatory cytokines, such as IL-4, IL-10 and IL-13 (produced by T helper 2 cells), can induce polarization of TAMs towards M2 phenotype and is associated with the expression of CD163 [15]. The gene discussed is IL13; the disease is neoplasm.