USP25Ubiquitin specific peptidase 25 is a protein that in humans is encoded by the USP25 gene.Functionis a highly conserved 76-amino acid protein involved in regulation of intracellular protein breakdown, cell cycle regulation, and stress response. Ubiquitin is released from degraded proteins by disassembly of the polyubiquitin chains, which is mediated by ubiquitin-specific proteases, such as USP25..