INCB054329 is a structurally distinct bromodomain and extraterminal domain (BET) inhibitor with IC50 values of 44 nM, 5 nM, 9 nM, 1 nM, 28 nM, 3 nM, 119 nM and 63 nM for BRD2-BD1, BRD2-BD2, BRD3-BD1, BRD3-BD2, BRD4-BD1, BRD4-BD2, BRDT-BD1 and BRDT-BD2, respectively.