USP7 is a deubiquitinase that removes K48-linked polyubiquitin chains from multiple substrates, regulating their stability and cellular localization. The enzyme contains a TRAF domain that facilitates substrate binding and is primarily localized to the cytosol and nuclear bodies. Beyond canonical protein stability regulation, USP7 participates in transcription-coupled nucleotide-excision repair, antiviral innate immunity, and modulation of circadian rhythms through its deubiquitinating activity. USP7 is frequently overexpressed across multiple cancer types including breast, prostate, colorectal, and lung cancers, where it promotes tumorigenesis by stabilizing oncogenic proteins 1. In non-small cell lung cancer, USP7 directly deubiquitinates KRAS at residue K147, stabilizing both wild-type and mutant KRAS and promoting cell proliferation; high USP7 expression correlates with poor survival 2. In glioblastoma, USP7 stabilizes the nuclear pore transporter KPNB1 through deubiquitination, which subsequently promotes a YBX1-NLGN3 signaling axis that drives tumor progression 3. USP7 also stabilizes HIF2α in clear cell renal cell carcinoma, supporting tumor growth in the context of VHL loss 4. Pharmacological USP7 inhibition has emerged as a therapeutic strategy. In gastric cancer, the USP7 inhibitor DHPO induces ferroptosis through stearoyl-CoA desaturase (SCD) degradation 5. USP7 inhibitors suppress non-small cell lung cancer proliferation, particularly in cells resistant to the KRAS-G12C inhibitor AMG510 2. Beyond cancer, USP7 knockdown reduces tau levels and rescues disease phenotypes in tauopathy mouse models by regulating CHIP-mediated tau proteostasis, suggesting potential utility in Alzheimer disease 6.