GGFG linker is a cleavable peptide linker used in antibody-drug conjugates (ADCs), GGFG refers to the glycyl-glycyl-phenylalanyl-glycine (GGFG) tetrapeptide sequence.
GGFG-based linkers are used in several ADCs, such as FDA-approved Trastuzumab deruxtecan, also known as ENHERTU.