FN1 and osteoarthritis: TGFBI is secreted into extracellular space and is predicted to bind fibronectin, collagen and integrins to mediate a multitude of physiologic and pathologic processes [48], including cell adhesion and migration [44], wound healing and response to injury [49], inflammation in osteoarthritis [50], tumorigenesis [51,52], and metastasis [53].