May have a role in chronic inflammations and may stimulate production of constitutive rather than inflammatory chemokines and cytokines. Forms a receptor signaling complex with TYROBP and triggers activation of the immune responses in macrophages and dendritic cells.

Expressed on macrophages and dendritic cells but not on granulocytes or monocytes. In the CNS strongest expression seen in the basal ganglia, corpus callosum, medulla oblongata and spinal cord.

Defects in TREM2 are a cause of polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL) [MIM:221770]; also known as presenile dementia with bone cysts or Nasu-Hakola disease (NHD). PLOSL is a recessively inherited disease characterized by a combination of psychotic symptoms rapidly progressing to presenile dementia and bone cysts restricted to wrists and ankles. PLOSL has a global distribution, although most of the patients have been diagnosed in Finland and Japan, with an estimated population prevalence of 2x10(-6) in the Finns.

Contains 1 Ig-like V-type (immunoglobulin-like) domain.

Secreted and Cell membrane.