PR-619 is widely used in biochemical and biomedical research as a potent inhibitor of deubiquitinating enzymes (DUBs). It enables scientists to study the ubiquitin-proteasome system, which plays a critical role in protein degradation and cellular regulation. By reversibly inhibiting DUB activity, PR-619 helps in identifying DUB substrates and understanding their involvement in signaling pathways linked to inflammation, DNA repair, and cancer progression. It is also employed in cellular assays to induce apoptosis and investigate mechanisms of cell death. Due to its cell permeability, PR-619 is effective in both in vitro and cell-based studies, making it a valuable tool for target validation and drug discovery in oncology and neurodegenerative disease research.