Galectins are a family of β-galactoside-binding proteins involved in the regulation of cell-cell and cell-matrix interactions.Galectin-1 can be either monomeric or homodimeric, and is present in a wide variety of cells and tissues. In humans, galectin-1 is a protein encoded by the LGALS1 gene. Secreted Galectin-1 is immunosuppressive and anti-inflammatory, inhibiting acute and chronic inflammation and autoimmunity. Mouse Galectin-1 has 88% sequence homology with human aa, 96% with rat aa, and 84% with equine, sheep, bovine, and porcine aa. Galectin-1 is highly expressed at the maternal-fetal interface and contributes to fetal immune amnesty. Its immunosuppressive properties also appear to allow tumor cells to evade immune detection.Galectin-1 regulates cell growth, proliferation, and induces apoptosis of activated T cells while modulating cytokine secretion or inhibiting pro-inflammatory cytokine production.