IRF4 and Miyoshi myopathy: The combination of PIs and PPIA inhibitors may enhance the therapeutic efficacy of PIs, resulting in more effective elimination of tumor cells.139 From the perspective of transcriptional regulators, in addition to a set of regulations shared between malignant and normal plasma cells (including XBP1, PRDM1, and IRF4), aberrantly activated transcriptional regulators ELF3 and TEAD in MM may indicate widespread alterations in cis-regulatory regions, suggesting a loss of lineage restriction rather than defective differentiation of MM cells.