PSMC4 (proteasome 26S subunit, ATPase 4) is a critical component of the 26S proteasome complex that functions as an AAA+ ATPase to unfold and translocate ubiquitinated proteins for degradation. As part of the heterohexameric AAA ring, PSMC4 plays essential roles in protein homeostasis by facilitating ATP-dependent proteolysis of misfolded, damaged, or regulatory proteins 1. The protein exhibits significant oncogenic potential across multiple cancer types, where overexpression correlates with poor prognosis and enhanced tumor progression 231. In prostate carcinoma, PSMC4 promotes progression through the CBX3-EGFR-PI3K-AKT-mTOR signaling pathway 2, while in low-grade gliomas, it regulates pathways including Notch, Toll-like receptor, and VEGF signaling 3. PSMC4 also functions in cellular processes beyond proteolysis, including cell extension formation in fibroblasts through Smad3 and ROCK signaling pathways 4. Additionally, PSMC4 serves as a component of immune-related prognostic signatures in osteosarcoma 5 and shows altered expression in dilated cardiomyopathy 6. The protein's expression can be downregulated by neurotoxic pesticides, potentially contributing to Parkinson's disease pathogenesis 7.