The PROTAC (PROteolysis TArgeting Chimera) technique was found during the identification of peptides or small chemical ligands that particularly bind with endogenous E3 ligases, including FBXW1A (F‐box/WD repeat‐containing protein 1A, also called b‐TRCP1), MDM2 (mouse double minute 2 homolog), the von Hippel‐Lindau tumour suppressor, and CRBN (cereblon).11, 12. Here, CRBN is linked to neoplasm.