The 26S proteasome is the major protease responsible for degradation of regulatory and abnormal proteins in the cell. Proteasomal degradation controls many cellular processes including, but not limited to, cell cycle control, transcription, DNA repair, apoptosis, quality control and antigen presentation. To elucidate how the proteasome is regulated is crucial to our understanding of the molecular details of proteasomal degradation and its functions in diverse biological pathways. In this article, I will highlight recent advances in understanding the proteasome structure and assembly and the regulation of proteasome gene expression. The implications of these new developments in cancer therapy will also be discussed.