The galectins are a family of beta-galactoside-binding proteins implicated in modulating cell-cell and cell-matrix interactions. Galectin 9 is an S-type lectin and an eosinophil chemoattractant (ECA) produced by antigen-activated T cells. Galectin 9 is involved in apoptosis, is thought to be a prognostic factor for breast cancer and is also overexpressed in Hodgkin's disease tissue. The protein has N- and C- terminal carbohydrate-binding domains connected by a link peptide. Multiple alternatively spliced transcript variants have been found for this gene.