The 26S proteasome system that degrades ubiquitinated proteins in an ATP-dependent manner is composed of 20S stacked core rings and 19S regulatory particles.44 PSMC2, a part of the 19S regulatory complex, is responsible for degrading ubiquitinated substrates into the 20S proteasome, and its expression is essential for 19S and 26S proteasome assembly.44, 45 Therefore, the decrease in the 26S protease regulatory subunit 7 reduced proteasome activity and sensitized the cancer cells toward cell death.44, 46. This evidence concerns the gene PSMC2 and cancer.