IRF4 and plasma cell myeloma: IRF4 is highly expressed in MM cells and is strictly required for MM cell survival, downregulating pro-apoptotic BCL2-modifying factor (BMF) and BCL2L11.583 Moreover, the oncogenic MAF bZIP transcription factor (MAF) activated enhancers and super-enhancers in B cells and plasma cells and cooperated with the plasma cell IRF4 to endow myeloma plasma cells with migratory and proliferative transcriptional potential.584 Overexpression of IRF4 and the oncogene c-Myc is a major mechanism of lenalidomide resistance in MM.