IRF8 and leukemia: This overlap contains 26 genes that are consistently downregulated and includes the critical regulators of myelopoiesis and leukemogenesis BCL2, C-MYC and IRF8. Although MLL fusion and NPM1c AML subtypes are associated with the aberrant expression of HOXA genes,16, 25 the common transcription program and the profound in vitro and in vivo effects of BET inhibitors in these leukemias are independent of downregulation of the HOXA genes.