Untreated (–) and treated (+) A431 whole cell extract (30 μg) were separated by 5% SDS-PAGE, and the membranes were blotted with EGFR (phospho Thr669) antibody [HL3425] (GTX641267) diluted at 1:1000 and EFGR antibody (GTX640663) diluted at 1:1000. The HRP-conjugated anti-rabbit IgG antibody (GTX213110-01) was used to detect the primary antibody