Resistance to apoptosis in EB-LCL with silencing for A20. The cell lines shown here were treated with H₂O₂ or etoposide (VP-16) and then subjected to a FACS assay 24 hours later to determine the proportion of annexin V–positive cells. The effects of A20 knockdown on induction of apoptosis by H₂O₂ and VP-16 were examined in triplicate. (A) Representative histograms. (B) The data of triplicate experiments are presented as mean ± SD.