• A family of large fibrous proteins that are the main components of connective tissue and are responsible for maintaining tissue structure.
  NCI
  U.S. National Cancer Institute, 2021
• A fibrous protein found in cartilage and other connective tissue.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• A fibrous protein that is the main component of connective tissue in the body.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• Principle protein of connective tissue; unusual absence of sulfur aminoacids; unique presence of hydroxyproline is believed to permit a triple helical fibrous structure.
  CRISP Thesaurus
  National Institutes of Health, 2006
• Collagen, any of a group of proteins that are components of whitish, rather inelastic fibres of great tensile strength present in tendon and ligament and in the connective tissue layer of the skin--dermis--and in dentin and cartilage. Collagenous fibres occur in bundles up to several hundred microns...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025