TREM1 (Triggering Receptor Expressed on myeloid cells 1) is a proinflammatory receptor expressed by phagocytes whose soluble form is increased in patients suffering from hepatitis B or C. Lymphocytic Choriomeningitis virus (LCMV) infection is used as a model for viral hepatitis in mice and Trem1-deficient mice infected with LCMV present an attenuated form of hepatitis. The gene discussed is TREM1; the disease is animal viral hepatitis.