Notably, treatment of NB4 APL cells in vitro with OSI-906 induced LSD1 upregulation (Supplementary Fig. 4g), reduced cell growth in a dose-dependent manner (Fig. 3g), while it increased significantly the frequency of colony-forming cells, even at the highest concentrations (Fig. 3h), an effect that is reminiscent of that of CR on APL in vivo (e.g., reduced cell proliferation and increased LIC frequency). Here, KDM1A is linked to acute promyelocytic leukemia.