Cynomolgus Monkey (Macaca fascicularis) CCL8 (C–C motif chemokine ligand 8, also known as MCP-2 – Monocyte Chemoattractant Protein-2) is a proinflammatory chemokine involved in leukocyte recruitment and regulation of inflammatory responses in nonhuman primates. CCL8 is a member of the CC chemokine family, which includes related chemokines such as CCL2 (MCP-1), CCL7 (MCP-3), and CCL13 (MCP-4) that coordinate monocyte and leukocyte trafficking during immune activation. In cynomolgus monkeys, CCL8 is produced by macrophages, fibroblasts, endothelial cells, epithelial cells, and other immune cells in response to infection, inflammatory cytokines, or tissue injury. CCL8 exerts its biological effects through interaction with chemokine receptors including CCR1, CCR2, CCR3, and CCR5, promoting chemotaxis and activation of monocytes, macrophages, dendritic cells, T lymphocytes, eosinophils, and basophils at sites of infection or inflammation. Because cynomolgus monkeys are widely used as preclinical animal models for human infectious diseases and immunology, CCL8 has been studied in models of viral infections, inflammatory diseases, and immune-mediated conditions, where chemokine-driven leukocyte recruitment is critical for both host defense and inflammatory pathology. Due to the close genetic and immunological similarity between cynomolgus monkeys and humans, CCL8 is important in translational research on chemokine signaling, immune regulation, and development of immunomodulatory therapies targeting inflammatory pathways.