HAVCR2 inhibits anti-tumor immunity by interacting with its ligand Galectin 9 (Gal9), phosphatidylserine (Ptdser) high mobility group box 1 (HMGB1), and carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1)[21]. The gene discussed is CEACAM1; the disease is neoplasm.