PSMD11 also known as S9, Rpn6 is a crucial regulatory subunit of the 26S proteasome, a complex responsible for the selective degradation of ubiquitinated proteins, which is vital for maintaining cellular homeostasis and regulating various cellular processes. PSMD11 consists of 422 amino acids and features a PCI domain, which is essential for its role in the ATP-dependent degradation pathway. Proper functioning of PSMD11 ensures that damaged or misfolded proteins are efficiently removed from the cell, preventing potential toxic accumulation that could lead to cellular dysfunction or disease. The gene encoding PSMD11 is located on human chromosome 17, a region that encompasses over 2.5% of the human genome and is known to encode more than 1,200 genes, highlighting PSMD11′s importance in cellular regulation and proteostasis.