Purity >95% as determined by SDS-PAGE. Macrophage inflammatory protein-3 beta (MIP-3-beta), also called CCL19, is a chemokine that is expressed in the thymus, lymph nodes, and activated bone marrow stromal cells. MIP-3-beta signals through the G protein-coupled receptor CCR7 to regulate normal lymphocyte recirculation. MIP-3-beta also functions during T cell trafficking to the thymus, and in T cell and B cell homing to the lymph nodes and secondary lymphoid organs. Human MIP-3-beta shows activity on mouse cells.