IRF4 and Miyoshi myopathy: Within the core gene set, we observed a down-regulation of the lymphocyte-specific transcription factor Interferon regulatory factor 4 (IRF4) mRNA (Figure 3B); it encodes a key transcriptional regulator of such pathway and is considered an “Achilles’ heel” in MM, since its targeting is lethal for MM cells, irrespective of their genetics.