Untreated (–) and treated (+) 293T whole cell extracts (30 μg) were separated by 5% SDS-PAGE, and the membrane was blotted with DNA-PKcs (phospho Ser2056) antibody [HL4206] (GTX643029) diluted at 1:1000. The HRP-conjugated anti-rabbit IgG antibody (GTX213110-01) was used to detect the primary antibody.