PMAIP1 and neuroblastoma: We therefore reduced NOXA expression by stably expressing short hairpins (sh) against NOXA or transfection of siRNA directed against NOXA, with both experimental methods resulting in reduced NOXA expression and protection of MYCN-amplified neuroblastoma cell lines from ABT-263-mediated apoptosis compared with controls (Figures 2A, 2B, S2A, and S2B).