CCL25/TECK is a CC chemokine is produced by stromal cells in the thymus and epithelial cells of the small intestine, particularly the jejunum and ileum. It binds to and induces chemoattraction through CCR9 on immature pre-T cells and thymocytes. CCL25 induces the homing of several lymphocyte populations to the small intestine, including Integrin a4b7+ gamma/delta T cells, Integrin aEb7+ CD8+ T cells, and IgA-producing plasma cells. In cancer, CCL25 promotes the metastasis of melanoma cells to the small intestine, the migration and invasion of some breast carcinomas, and the attraction of mesenchymal stromal cells to multiple myelomas. CCL25 attracts CCR9+ monocytes and macrophages in rheumatoid arthritis and CCR9+ macrophages in atherosclerosis.