JQ-1 (carboxylic acid) -NH-C2-NH-COOH is a conjugate of E3 ligase ligand and linker (E3 Ligase Ligand-Linker Conjugates), which is composed of JQ-1 carboxylic acid and the corresponding linker: (2-Aminoethyl)carbamic acid. JQ-1 (carboxylic acid) -NH-C2-NH-COOH can be used as a Cereblon ligand to recruit CRBN protein and as a key intermediate for the synthesis of complete PROTACs molecules.