The extracellular region of T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) consists of an IgV domain, a mucin domain, and a stalk domain. The transmembrane region consists of a transmembrane domain and the intracellular region consists of a cytoplasmic tail with five tyrosine residues. The IgV domain contains binding sites for its ligands. Phosphatidylserine (Ptdser), carcinoembryonic antigen-related cell adhesion molecule (CEACAM1), and high mobility group box 1 (HMGB1) bind to the FG-CC’ loop, while Gal9 binds to the N-linked glycan.