The galectins are a family of beta-galactoside-binding proteins implicated in modulating cell-cell and cell-matrix interactions. LGALS3BP is a widely expressed,secreted galectin. It has been found elevated in the serum of patients with various types of breast,lung,colorectal,ovary,and endometrial cancer,and in those infected by the human immunodeficiency virus (HIV). High expression levels of LGALS3BP are associated with a shorter survival,the occurrence of metastasis or a reduced response to chemotherapy. The native protein binds specifically to a human macrophage-associated lectin known as Mac-2 and also binds galectin 1. It appears to be implicated in immune response associated with natural killer (NK) and lymphokine-activated killer (LAK) cell cytotoxicity. Immunoblotting showed that LGALS3BP is likely contained in breast milk,serum,semen,saliva,urine,and tears.