Studies revealed enhanced expression level of LGALS1 in NPC-derived Tregs, which was reported to mediate immunosuppression by upregulation of cell-surface programmed death-ligand 1 (PD-L1) and galectin-9 (Gal-9) in head and neck cancer (18, 40). The gene discussed is LGALS9; the disease is nasopharyngeal carcinoma.