Untreated (–) and treated (+) HeLa whole cell extracts (30 μg) were separated by 12% SDS-PAGE, and the membrane was blotted with SMAD3 (phospho Ser423/425) antibody (GTX129841) diluted at 1:500.

Untreated (–) and treated (+) NIH-3T3 whole cell extracts (30 μg) were separated by 10% SDS-PAGE, and the membrane was blotted with SMAD3 (phospho Ser423/425) antibody (GTX129841) diluted at 1:500. The HRP-conjugated anti-rabbit IgG antibody (GTX213110-01) was used to detect the primary antibody.