XIAP and acute lymphoblastic leukemia: To our surprise, we observed that NALM‐6 cells with strong XIAP KD, using the strong SFFV promoter and two distinct shRNA sequences, spontaneously died over time in vitro and in vivo, indicating a yet unknown, genuine essential function of XIAP alone in r/r ALL (Fig 4G and Appendix Fig S3E and F).