Regulates immune responses through the recognition of cell-surface glycans. Essential for the anergy and suppressive function of CD25-positive regulatory T-cells (Treg). Interacts with CEL. Localized in granules from where it may be secreted or transported to other locations in the cell. Expressed abundantly in the bone marrow. Expressed exclusively by eosinophils and basophils. Not detected in monocytes and neutrophils. Expressed in CD25-positive regulatory T-cells (Treg) (at protein level). Found in intestinal tissue from patients with Celiac disease, expression is directly related to the histological grade of mucosal damage and to the number of eosinophils found in the duodenal lesion (at protein level). Found in sputum of patients with eosinophilic inflammatory diseases such as asthma (at protein level). Forms hexagonal bipyramidal crystals, known as Charcot-Leyden crystals, in tissues and secretions from sites of eosinophil-associated inflammation and some myeloid leukemias. Was originally thought to possess lysophospholipase activity but the absence of this activity has been shown by PubMed:11834744. Galectin-10