KB02-JQ1 is a potent and specific proteolysis targeting chimera (PROTAC) that specifically degrades BRD4, acting as a molecular glue. It does not degrade BRD2 or BRD3. The mechanism of action involves covalent modification of the E3 ligase DCAF16, thereby promoting BRD4 degradation. Importantly, KB02-JQ1 demonstrates enhanced stability and durability in facilitating protein degradation within biological systems. The compound forms a complex with the ubiquitin E3 ligase ligand KB02 through a linker, resulting in the formation of KB02-JQ1[1].