Galectin-9 has been identified as a major ligand for TIM-3 and is a member of the galectin family.27 It can regulate diverse biological functions of tumour cells, aggregation, adhesion and apoptosis.28 When TIM-3 binds to its ligand galectin-9, it can inhibit the expansion of Th1 and Th17 cells. Here, LGALS9 is linked to neoplasm.