ABSTRACT: Col1a1 is located on mouse distal chromosome 11 (Celera 94607393-94622990bp; 15kb) and encodes type I procollagen that associates stoichiometrically with col1a2 in forming secreted type I mature collagen that self-assembles into a supramolecular fibrillar structure consisting of a protein family. Type I collagens are predominantly enriched in bone, cartilage, skin, tendons, and eye (i.e. in major fibrous tissues) making up the main extracellular matrix (ECM) component for support and scaffolding purposes. Col1a1 is known to be expressed in the embryo (E9.5; Northern dot blot), perioptic mesenchyme (E11), cornea (E11), skeleton (E14.5), brain meninges (E14.5), and cartilage (E14.5) at relatively early stages. Most evidence of type I collagen function is coupled to the latter stages of skeletal development, thus bypassing the major events of axis formation, tissue differentiation, and mesenchlymal-epithial interactions, for example, that are more symbolic of morphogens and growth factors. Members of the integrin cell surface receptor family of molecules mediate cell adhesion to ECM proteins such as collagen (mainly to type IV basement membrane collagen that forms into a polygonal meshwork), fibronectin, and laminin implicated in wound healing and inflammatory responses (e.g. Crohn disease, ulcerative colitis) in connective tissues. There is some evidence for protein-protein interactions between leukocyte-associated integrins and the interstitial matrix in promoting the migration and/or activation of extravasated leukocytes (e.g., T cells and monocytes) within the perivascular compartment, an ECM-rich environment. This region is surmised to be an important location where certain human leukocytes undergo differentiation (e.g. monocytes) and activation (neutrophils, monocytes, lymphocytes) upon extravascular migration. The von Willebrand factor (vWF), type C motif is found in various plasma proteins like complement factors, the integrins, collagen types, and other extracellular proteins. Thus, the majority of vWF-containing proteins are extracellular and a common feature appears to be involvement in multi protein complexes participating in numerous biological events (e.g. cell adhesion, migration, homing, pattern formation, and signal transduction).