Conflict-of-interest disclosure: A.E.D. served as chair of a data safety monitoring committee for Geron; holds consultancy roles for Geron, Novartis, and Bristol Myers Squibb (BMS); and holds memberships on boards or advisory committees in Geron, Novartis, BMS, and Takeda. R.C.L. reports consultancy fees from Takeda, bluebird bio, and Thermo Fisher Scientific. R.B. reports employment and stock in a private company, Aptose Biosciences; serves as chair of data safety monitoring committee in Gilead and Epizyme; holds membership on board or advisory committee in Silence Therapeutics; and research funding from Takeda. T.A.B. reports stock in a private companies BMS, AstraZeneca, Epizyme, and Heron Therapeutics; and holds memberships on boards or advisory committees in BMS, MorphoSys, Karyopharm, and Cardinal Health. E.P. reports research funding from BMS and Kura; honoraria from Taiho and Blueprint; and research funding from Incyte. R.S.K. reports honoraria from Novartis, Geron, and Acceleron; and honoraria and speakers bureau fees from Agios, AbbVie, Jazz Pharmaceuticals, and BMS. M.A.S. reports memberships on boards or advisory committees of Novartis, Takeda/Millenium, and BMS. The remaining authors declare no competing financial interests.