IL10 and neoplasm: Based on their role, several distinct subsets of macrophages have been defined: (1) classically activated macrophages (M1) which mediate antimicrobial defense via secretion of pro-inflammatory cytokines, (2) alternatively activated macrophages (M2) with anti-inflammatory function, (3) regulatory macrophages (Mregs) which secrete large amounts of IL10, (4) tumor-associated macrophages (TAMs) which suppress anti-tumor immunity, and finally (5) myeloid-derived suppressor cells (MDSCs) as a group of immature cells linked to TAMs [125].