FN1 and colon carcinoma: Since knockdown experiments MEFs [21] and human colon carcinoma cells [25] support the importance of Rgnef in promoting cell motility, Rgnef−/− and Rgnef+/+ MEFs were analyzed by scratch wound (Figs. 3C and D, Videos S1 and S2) and FN-stimulated haptotaxis transwell (Fig. 3E) migration assays.