We interrogated gene expression profiles (GEP) from the randomized, phase 3 Assessment of Proteasome Inhibition for Extending Remissions (APEX) study that compared BTZ with high-dose dexamethasone (DEX) in RRMM patients ....Using the CoMMpass database, increased PSMC2 expression also correlated with a worse OS (Figure 1B), while increased PSMC6 correlated with worse OS as well as progression free survival (PFS) (OS- HR= 2.29 p=0.0014, PFS- HR=1.63 p=0.0109)....Taken together, our results indicate that increased PSMC2 and PSMC6 correlates with OS in MM in both patients treated with BTZ in the APEX and with a variety of standard therapies in the CoMMpass database.