Mc-Val-Cit-PAB is a peptide linker molecule used in the synthesis of antibody-drug conjugates (ADCs). It contains a maleimidocaproyl (Mc) group that can be conjugated to an antibody and a p-aminobenzyl (PAB) spacer that allows the peptide to be linked to active compounds, such as anticancer agents. Mc-Val-Cit-PAB is cleaved in vivo by cathepsin B, a protease highly expressed in cancer cells, which confers specificity of the ADC to cancer cells.

[1] Anti-cd70 antibody-drug conjugates and their use for the treatment of cancer and immune disorders.