Chemotactic for lymphocytes and monocytes. Is a ligand for CCR1, CCR3 and CCR5. Is an inhibitor of HIV-1-infection. The processed form LD78-beta(3-70) shows a 20-fold to 30-fold higher chemotactic activity and is a very potent inhibitor of HIV-1-infection. LD78-beta(3-70) is also a ligand for CCR1, CCR3 and CCR5. The N-terminal processed forms LD78-beta(3-70) and LD78-beta(5-70) are produced by proteolytic cleavage after secretion from peripheral blood monocytes. The cleavage to yield LD78-beta(3-70) is probably achieved by DPP4. The copy number of the CCL3L1 gene varies among individuals; most individuals have 1-6 copies in the diploid genome, although rare individuals have zero or more than 6 copies. Belongs to the intercrine beta (chemokine CC) family.