Untreated (–) and treated (+) A431 whole cell extracts (30 μg) were separated by 10% SDS-PAGE, and the membrane was blotted with RSK3 (phospho Thr356/Ser360) antibody (GTX133613) diluted at 1:1000. The HRP-conjugated anti-rabbit IgG antibody (GTX213110-01) was used to detect the primary antibody.