TIM-1 (T cell immunoglobulin and mucin domain 1), also known as KIM-1 and HAVcr1, is expressed on many immune cell types and epithelial cells. It binds to phosphatidylserine (PS), LMIR5/CD300b, TIM-1 (homophilic), TIM-4, IgA, and the glycoproteins of a number of enveloped viruses. Its interaction with PS enables TIM-1 to mediate the phagocytosis and clearance of apoptotic cells. TIM-1 signaling costimulates T cell activation and enhances Th2 cytokine production. TIM-1 serves as a cellular entry receptor for hepatitis A virus, Ebolavirus and Marburgvirus. Polymorphisms are associated with susceptibility to atopy, autoimmunity, and severe hepatitis A virus infection in humans. A soluble form of TIM-1 is elevated in the urine during nephropathy.