An inhibitor of the Bromodomain and Extra-Terminal (BET) family of bromodomain-containing proteins with potential antineoplastic activity. Upon administration, the BET inhibitor INCB054329 binds to the acetylated lysine recognition motifs on the bromodomain of BET proteins, thereby preventing the interaction between the BET proteins and acetylated histones. This disrupts chromatin remodeling and gene expression. Prevention of the expression of certain growth-promoting genes may lead to an inhibition of tumor cell growth. Characterized by a tandem repeat of bromodomain at the N-terminus, BET proteins, BRD2, BRD3, BRD4 and BRDT, are transcriptional regulators that play an important role during cellular growth.