Indicator Explainer
Calprotectin
A heterodimeric or heterotetrameric protein complex comprised of protein S100A8 and protein S100A9. This complex is expressed in the cytosol of neutrophils and macrophages and plays a role in multiple host defense related processes including immunomodulation, neutrophil chemotaxis and both antibacterial and antifungal responses.
This page explains what the indicator is and how results are interpreted in general terms. Reference ranges depend on the laboratory, the method, and your own situation — no single “normal value” applies to everyone. This page is health information, not a diagnosis. For symptoms, treatment, or urgent concerns, contact a healthcare professional.
When it is tested
Source: National Cancer Institute, NCI Thesaurus 26.09d, C105971. NCI definition, reproduced without modification under CC BY 4.0. Source identity and definition checked automatically on 2026-10-20. No individual clinical interpretation or human reviewer is asserted.
Reading results
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.