The YY1-RelA complex was shown to directly bind and repress the pro-apoptotic Bim gene in MM cells and depletion of YY1 or RelA completely impaired the colony forming ability of MM progenitor cells, suggesting that RelA-YY1 complex formation (Figure 4) is absolutely essential for the survival and growth of MM cancer cells (41). This evidence concerns the gene YY1 and Miyoshi myopathy.