M2 type macrophages closely resemble tumor-associated macrophages (TAMs) and are characterized by increased expression of IFN-γ, CCL2, CCL5, CXCL16, CXCL10, CXCL9, TNF-α, MMP9 and IL-10, arginase-1, and peroxisome proliferator-activated receptor-γ (PPAR-γ) [36]. This evidence concerns the gene MMP9 and neoplasm.