Western blot analysis of A431 cells serum starved overnight (lanes 1, 3, & 5) and treated with pervanadate (1 mM) for 30 min (lanes 2, 4, & 6). The blots were probed with rabbit polyclonal anti-Integrin β4 (Tyr-1526) (lanes 1 & 2) and anti-Integrin β4 (Tyr-1494) (lanes 3 & 4) or with mouse monoclonal anti-Integrin β4 (lanes 5 & 6).