Cynomolgus Monkey (Macaca fascicularis) C-Reactive Protein (CRP) is an acute-phase protein belonging to the pentraxin family, which also includes serum amyloid P component (SAP) and pentraxin 3 (PTX3)—proteins involved in innate immune defense and inflammatory responses. In cynomolgus monkeys, CRP is primarily produced by hepatocytes in the liver in response to proinflammatory cytokines, particularly interleukin-6 (IL-6), as well as IL-1β and TNF-α, during infection, tissue injury, or inflammatory disease. CRP binds to phosphocholine residues on microbial membranes and damaged host cells, promoting complement activation and opsonization, thereby enhancing phagocytosis and clearance of pathogens and cellular debris. In cynomolgus monkeys, CRP functions as a sensitive biomarker of systemic inflammation, with increased circulating levels observed during infectious diseases, inflammatory conditions, and tissue injury. Because cynomolgus monkeys share close genetic, physiological, and immunological similarities with humans, CRP responses in this species closely resemble those in humans, making them important preclinical animal models for studying systemic inflammation, cardiovascular disease, infectious disease, and immune-mediated disorders. Consequently, cynomolgus monkey CRP is widely used in translational biomedical research and drug development to monitor inflammatory responses, disease progression, and therapeutic efficacy in studies relevant to human health.