IRF4 and primary effusion lymphoma: Disruption of the IKZF1/3-IRF4-MYC transcriptional axis is of specific importance in MM [39,49], as studies have shown that in other diseases, such as primary effusion lymphoma, degradation of IKZF1/3 is uncoupled from lenalidomide-induced suppression of IRF4 and MYC [50].