Used primarily as a dipeptide linker in antibody-drug conjugates (ADCs), enabling targeted delivery of cytotoxic agents to cancer cells. Its structure is designed to remain stable in circulation but release the drug inside the target cell upon lysosomal degradation. The Val-Cit linker is especially valued for its cleavage by cathepsin B, an enzyme overexpressed in many tumor tissues. This selective activation enhances therapeutic efficacy while reducing systemic toxicity. Commonly paired with payloads like monomethyl auristatin E (MMAE), it plays a critical role in the design of modern ADCs for oncology applications.