PROTAC BET-binding moiety 1 is a key intermediate for the synthesis of high-affinity BET inhibitors.In Vitro: The bromodomain and extra-terminal (BET) family proteins, consisting of BRD2, BRD3, BRD4, and testis-specific BRDT members, are epigenetic “readers” and play a key role in the regulation of gene transcription. BET proteins are considered to be attractive therapeutic targets for cancer and other human diseases.