Notes: VH 032 linker 6 is a precursor in the synthesis of proteolysis-targeting chimeras (PROTACs) that contains a terminal alkyne conjugated via a PEG linker to VHL ligand 1 (Item No. 21591), which binds to VHL E3 ligase.{67451} It has been used in the synthesis of PROTACs targeting Bcl-xL in senescent cells.