Quantification of (G) Cdc42, (H) Rac1 and (I) RhoA activation by immunoblotting subsequent to seeding HUVECs on E7, Fn or a combination of both. Preferentially, E7 activated Cdc42 and Fn activated Rac1, but both proteins antagonized each other. None of the treatments affected RhoA signaling (n = 3; one-way ANOVA). IP-immunoprecipitation, AU-arbitrary units 