FN1 and neoplasm: Although the ECM protein, fibronectin, is not normally found in adult tissue, it is a very abundant component of the tumor-associated ECM (Zetter, 1993), and the cell's major fibronectin-binding integrin (α5β1) is key to the survival (Lee and Juliano, 2000; O'Brien et al., 1996; Zhang et al., 1995) and migration (Caswell et al., 2007, 2008; Muller et al., 2009) of tumor cells.