DRAP1 (DR1 associated protein 1) is a transcriptional corepressor that functions primarily as a component of the DR1/DRAP1 heterodimeric complex to suppress RNA polymerase II transcription. The DR1/DRAP1 complex binds to the TATA-binding protein (TBP) and blocks preinitiation complex assembly by preventing TFIIA and TFIIB recruitment, thereby repressing both basal and activated transcription of class II genes 1. This repressor complex functions globally across tissues, with particularly high expression in differentiated, non-dividing cells 1. In cancer contexts, DRAP1 is upregulated in triple-negative breast cancer, where the DR1/DRAP1 complex represses CASTOR1 expression to increase mTOR signaling, promoting tumor proliferation, migration, invasion, and metastasis 2. The complex exhibits a positive feedback loop wherein DRAP1 recruits deubiquitinase USP7 to stabilize DR1, while DR1 directly activates DRAP1 transcription 2. Beyond cancer, DRAP1 functions in Nodal signaling during vertebrate embryonic development 3 and has been identified as a key regulatory node in coronary artery disease molecular networks 4. DRAP1 expression correlates with prognosis in renal cell carcinoma and chemotherapy response in colorectal cancer, suggesting clinical significance as a biomarker and therapeutic target 5, 6.