Differentiation arrest and dependence on oxidative metabolism are features shared among genetically diverse acute myeloid leukemias (AML). A phenotypic CRISPR-Cas9 screen in AML identified dependence on phosphoseryl-tRNA kinase (PSTK), an atypical kinase required for the biosynthesis of all selenoproteins. In vivo, PSTK inhibition (PSTKi) impaired AML cell growth and leukemic stem cell self-renewal. Notably, timed pharmacologic PSTKi effectively targeted chemo-resistant AML in murine …