MMP9 and neoplasm: Compared with peripheral blood M2 macrophages, tissues/paratumor tissue M2 macrophages highly expressed the marker gene MCR1 (CD206) and the protumorigenic genes TGF-β, IL10, VEGFA and MMP9, which indicated stronger protumorigenic and immunosuppressive properties, and MCR1 may be a better marker to filter tumor-infiltrating M2 macrophages.