Oxidative functions of polymorphonuclear neutrophils (PMNs), which play a deciding role in the phagocytosis process, are stimulated by extracellular matrix proteins such as type I collagen. Previous studies have demonstrated the involvement of a DGGRYY sequence located within the a1 chain C-terminal telopeptide in type I collagen-induced PMN activation, but so far the mechanism has not been completely elucidated.