DNA–PK expression significantly affects PB transposition in PIEC cells. (A) Overexpression of Ku70, Ku80, or DNA-PKcs facilitates PB transposition in PIEC cells. *P < 0.01, **P < 0.001. (B) Knockdown of Ku70, Ku80, or DNA-PKcs in PIEC cells suppresses PB transposition. RNAi target antisense sequences are listed in Table S4. *P < 0.05, **P < 0.01. Error bars were plotted by the standard error of the mean (SEM).