BBC0403 is a selective BRD2 inhibitor with K d s of 7.64 μM and 41.37 μM for BRD2 (BD2) and BRD2 (BD1) , respectively. BBC0403 exhibitS higher binding specificity for BRD2 compared to BRD3 and BRD4. BBC0403 has the potential for osteoarthritis (OA) research.