Cynomolgus Monkey (Macaca fascicularis) CCL3 (C-C motif chemokine ligand 3, also known as MIP-1α, macrophage inflammatory protein-1 alpha) is a pro-inflammatory chemokine that plays an important role in recruitment and activation of immune cells during inflammatory and infectious responses in nonhuman primates. CCL3 primarily signals through the CCR1 and CCR5 receptors, promoting chemotaxis of monocytes, macrophages, dendritic cells, natural killer (NK) cells, and activated T lymphocytes to sites of infection or tissue injury. In cynomolgus monkeys, CCL3 is produced by activated macrophages, dendritic cells, epithelial cells, and lymphocytes in response to inflammatory stimuli such as pathogen-associated molecules and cytokines including TNF-α and IL-1β. Because cynomolgus monkeys are widely used in preclinical infectious disease and immunology research, CCL3 is studied in models of viral infections (such as dengue, influenza, and SARS-CoV-2), tuberculosis, and inflammatory diseases, where recruitment of monocytes and T cells contributes to immune activation and pathogen control. CCL3-mediated signaling also influences immune cell infiltration and inflammatory responses in tissues during disease progression. As a regulator of leukocyte trafficking and inflammatory signaling, cynomolgus monkey CCL3 is important for studies of host–pathogen interactions, immune regulation, and evaluation of immunomodulatory therapeutics, providing translational insight into chemokine-driven immune responses relevant to human disease.