To determine whether Ku70 depletion-induced reduction of cell viability is specific to only one type of N-type NB cells, SH-SY5Y cells, we determined cell viability in three other N-type NB cells (IMR32, KCN-69n, and GOTO) after Ku70 depletion using siRNA. This evidence concerns the gene XRCC6 and neuroblastoma.