Fig. (1) Macrophages, heterogeneous cell populations. (A) Th1 induction of M1 through interferon-gamma signaling. M1 releases specific cytokines and chemokines as part of the proinflammatory response. (B) M2 differentiation via IL-13 and IL-4 released from Th2, mast cells, and basophils. Differentiated M2 then releases factors that favor the anti-inflammatory and immunosuppressive responses. (C) Ms deactivation through the IL-10, TGF-beta, and IFN-alpha/beta signaling. Deactivation downregulates the expression of MHC class II and increases the uptake of apoptotic cells, resulting in an anti-inflammatory and immunosuppressive response. (D) Macrophages differentiation towards a specific phenotype present in the tumorous environment (TAMs), where they release large amount of immunosuppressive cytokines and a little amount of pro-inflammatory cytokines indirectly promoting the development of cancer. CTLs: Th1-cytotoxic T cells ; IFN: Interferon ; IL: Interleukine ; MHC: Major Histocompatibility Complex ; MIP: Macrophage Inflammatory Protein ; TNF: Tumor Necrosis Factor ; TAMs: Tumor Associated Macrophages ; Th: T helper ; Rc: Receptor ; CCL : C-C Motif Chemokine Ligand ; M : Macrophage ; MDC : Macrophage-Derived Chemokine ; RANTES : Regulated on Activation, Normal T cell Expressed and Secreted ; TGF : Transforming Growth Factor.