C-Reactive Protein (CRP) is a major acute-phase biomarker of inflammation, widely used in clinical and research settings. Produced primarily by the liver in response to interleukin-6 (IL-6), CRP circulates as a pentamer (pCRP) that can dissociate into monomeric CRP (mCRP), each isoform exhibiting distinct roles in immune signaling and vascular inflammation. CRP binds phosphocholine on pathogens and apoptotic cells, activates the classical complement pathway via C1q, and interacts with Fcγ receptors, linking innate immunity with adaptive responses. In diagnostics, high-sensitivity CRP (hs-CRP) assays are routinely employed to assess cardiovascular disease risk, predict myocardial infarction or stroke, and monitor systemic inflammation in autoimmune and infectious diseases. CRP is also increasingly studied for its role in chronic inflammatory and neurodegenerative disorders, where isoform-specific activity may drive tissue injury. Catalina’s high-quality CRP antibodies enable precise detection with proven sensitivity and specificity, supporting advanced research in inflammation, cardiovascular biology, autoimmunity, and translational medicine.