NRF1 and Miyoshi myopathy: MM cells also exhibit baseline NRF1 activation and strongly depend on DDI2 for survival, and DDI2 knockout is cytotoxic to MM cells both in vitro and in vivo [Recent studies have shown that DDI2 knockout prevents proteolytic processing and nuclear translocation of NRF1, causing impaired proteasome activity recovery upon irreversible proteasome inhibition and thereby increasing sensitivity to PIs.