MYBBP1A (MYB binding protein 1a) is a multifunctional nuclear protein that serves as a transcriptional coregulator with both tumor suppressor and metabolic regulatory functions. The protein acts as a transcriptional corepressor that interacts with sequence-specific DNA-binding proteins and regulates gene expression through multiple mechanisms 1. MYBBP1A plays a critical role in p53 signaling pathway regulation, where it can activate p53 through interactions with p300-mediated acetylation, forming feedback loops that control cell cycle arrest and apoptosis 12. In metabolic regulation, MYBBP1A functions as a tumor suppressor by repressing PGC1α and c-MYB, thereby controlling the metabolic switch between glycolysis and oxidative phosphorylation 3. Loss of MYBBP1A promotes tumor cell adaptation to harsh microenvironments and increases tumorigenesis in low-glucose conditions 3. The protein exhibits tissue-specific functions in cancer progression, showing opposing roles in cell proliferation versus migration in head and neck squamous cell carcinoma 4. MYBBP1A also contributes to viral replication, as demonstrated in HSV-1 infections where it promotes viral gene expression and replication 5. Additionally, genetic polymorphisms in MYBBP1A are associated with tuberculosis susceptibility and drug response in various cancer types 67.