TREM2 and neoplasm: As TAM are frequently described as type 2 or alternatively activated macrophages that facilitate tumor growth, we hypothesized that a counteracting TREM receptor, such as TREM-2, might be expressed on these cells since this TREM is generally considered anti-inflammatory, has been shown to be expressed on alternatively activated macrophages, and has been associated with a type 2 macrophage gene signature (9, 30, 31).