Fibulins are a family of 7 extracellular calcium binding proteins that have developmental roles (Twal et al. 2001). Fibulins 1-5 are found in association with elastic fibers. Fibulin-1 binds fibronectin (Balbona et al. 1992, Tran et al. 1997) suppressing fibronectin-mediated inhibitory effects on cell attachment and spreading (Twal et al. 2001). Fibulin-2 also binds fibronectin (Sasaki et al. 1995).