The concept of proteolytic targeting chimera (PROTAC) was first proposed by Crews and Deshaies laboratory in 2001, the team successfully achieved the degradation of methionyl aminopeptidase 2 (MetAp-2) by PROTAC method. Since then, PROTACs targeting androgen receptor (AR) and estrogen receptor (ER) have appeared one after another. In 2004, a PROTAC molecule that recruited the tumor suppressor protein VHL through a polypeptide fragment on HIF1-α showed a greater improvement in membrane permeability and could also exist stably in cells. However, these peptide-based PROTAC molecules were not ready for drug preparation. Until 2008, when the first small-molecule E3 ubiquitinase ligand-based PROTAC came out, marking the beginning of small-molecule PROTAC research, and…