ITGAM and neoplasm: While CD11b+Ly6cloMHCIIhi M1-like macrophages, or classically activated macrophages, are activated by IFN-γ and sterile or infectious injury, and are tumoricidal17; alternative activated M2TAMs, defined as CD11b+Ly6c−MHCIIlo, support tumor progression and metastasis through remodeling of extracellular matrix and release of factors that promote cell proliferation, angiogenesis and migration.18