MYCBP (MYC binding protein) is a transcriptional coactivator that regulates MYC-mediated gene expression and plays critical roles in cancer progression. The protein functions by directly binding to the oncogenic transcription factor c-MYC and enhancing its transcriptional activity 1. MYCBP operates through multiple mechanisms, including protein stabilization and regulation of downstream c-MYC targets such as CCND1, c-Jun, and CDK4 1. The protein can be stabilized through deubiquitination by enzymes like USP25 and protected from ubiquitin-mediated proteasome degradation by circular RNAs 21. MYCBP demonstrates significant disease relevance across multiple cancer types. It is overexpressed in gastric cancer, where it promotes invasion and migration through the β-catenin/LEF-1 pathway 3. In triple-negative breast cancer, MYCBP expression correlates with enhanced proliferation and epithelial-mesenchymal transition, while being negatively regulated by miR-26b-5p 4. Additionally, MYCBP participates in chr1 rearrangements, forming fusion proteins like MYCBP::EHD2 in T-cell acute lymphoblastic leukemia 5. Clinically, MYCBP represents a promising therapeutic target, as its suppression disrupts malignant phenotypes across various cancer types 24. The protein also functions in normal development, particularly in Drosophila germline differentiation where it forms complexes with Otu protein to regulate sex determination 6.