As hetero-bifunctional molecules, PROTAC molecules contain two ligands to bind target proteins and E3 ubiquitin ligases. After binding with dual molecules, the E3 ubiquitin ligase will lead the given target protein to its degradation. Being a vital part of the PROTAC molecules, a functional E3 ligase ligand is required to successfully degrade the protein targets. Although more than 600 E3 ubiquitin ligases have been founded in humans, the most popular E3 ubiquitin ligases successfully applied in small PROTAC molecules are among cereblon (CRBN), Von-Hippel-Lindau (VHL), cell inhibitor of apoptosis protein (cIAP), and murine double minute 2 (MDM2). Creative Biolabs provides a pool of ready-to-use E3 ligase ligands. We also have the related service to discover a totally new E3 ligase ligand not mentioned above. E3 ligase ligand https://www.creative-biolabs.com/protac/category-e3-ligase-ligand-336.htm