Galactose lectin-3 (Galectin-3) belongs to the lectin family and is expressed in the nucleus, cytoplasm, mitochondria, cell surface, and extracellularly.Galectin-3 has an affinity for β-galactosidase and exhibits anti-bacterial and antifungal activity. It is involved in many biological processes such as cell adhesion, cell activation and chemotaxis, cell growth and differentiation, cell cycle, and apoptosis. Based on its wide range of biological functions, Galectin-3 is thought to be associated with cancer, inflammation and fibrosis, heart disease, stroke, etc. Galectin-3 expression levels have been correlated with various types of fibrosis. Galectin-3 expression is upregulated in liver fibrosis, renal fibrosis, and idiopathic pulmonary fibrosis (IPF). In acute decompensated heart failure and chronic heart failure populations, high expression of Galectin-3 resulted in a higher risk of death. Meanwhile, Galectin-3 is thought to have an important role in tumor metastasis.