Macrophage Inflammatory Protein 1 alpha (MIP1 alpha) and MIP1 beta, two closely related but distinct proteins, were originally co-purified from medium conditioned by a LPS-stimulated murine macrophage cell line. Mature mouse MIP1 alpha shares approximately 77% and 70% amino acid identity with human MIP1 alpha and mouse MIP1 beta, respectively. MIP1 proteins are expressed primarily in T cells, B cells, and monocytes after antigen or mitogen stimulation. Has adhesive effects on lymphocytes. M