The M1 phenotype is functionally distinguished by its ability to eliminate microorganisms or tumor cells, and to secrete proinflammatory cytokines, such as IL-23, IL-12, IL-6, IL-1β, tumor necrosis factor α (TNF-α), with production of reactive oxygen species (ROS), and a low expression of IL-10 favoring the polarization of T helper cells to Th1 lymphocytes (19, 20); while M2 phenotype is characterized by a low expression of MHC-II, IL-12, IL-23 and a high expression of arginase 1 (Arg1) and anti-inflammatory cytokines, such as TGF-β and IL-10. Here, ARG1 is linked to neoplasm.