FIGURE 2.

Molecular structure of human T‐cell immunoglobulin and mucin domain containing‐3 (TIM‐3) and its ligands. Galectin‐9, phosphatidylserine (PtdSer), high‐mobility group box 1 (HMGB1), and carcinoembryonic antigen–related cell adhesion molecule 1 (CEACAM1) have been identified as TIM‐3 ligands. Galectin‐9 binds to TIM‐3 via the glycosylation sites of the IgV domain, whereas ligation of PtdSer and CEACAM1 can occur in the FG‐CC cleft. The cytoplasmic tail of TIM‐3 has one Src homology 2 (SH2) binding motif and six tyrosine residues