BRD4 and neoplasm: In addition, Yu et al. used this in situ bioorthogonal tumor targeting strategy to design a poly-PROTAC (POLY-PROTAC) nanoplatform for targeted degradation of BRD4, which improved tumor selectivity and precise delivery of proteolysis targeting chimeras (PROTACs).141 DBCO-modified POLY-PROTAC achieved selective tumor targeting and retention by bioorthogonal reaction with N3-modified self-assembled micelles that enter the tumor beforehand, resulting in an approximately 1.9-fold increase in nanoparticle accumulation in the tumor compared to the group without bioorthogonal reaction.