Our paper reported that FLT3-ITD-positive AML cells are addicted to HSP90 activity, and that the HSP90 family member GRP94 is required for aberrant endoplasmic reticulum retention of FLT3-ITD. We have reason to question the provenance of the data shown in Figures 2E, 2F, 2G, 2H, 4A, 4C, 5D, 5E, S2A, S2D, S2E, S3B, S3F, S4E, S4F and S4I, as well as the zebrafish images shown in Figure 7, all of which were prepared by the first author of the article. The figures provided by all other authors are not in question. While we believe the overall conclusions of our manuscript remain intact, the most appropriate course of action is to retract the paper. All authors have agreed to this Retraction. We deeply regret this circumstance and apologize to the scientific community for the inconvenience that this may have caused.