Gly-Gly-Phe-Gly-NH-CH2-O-CH2COOH GMP is a GMP grade Gly-Gly-Phe-Gly-NH-CH2-O-CH2COOH (HY-45672). Gly-Gly-Phe-Gly-NH-CH2-O-CH2COOH is an ADC Linker that can be used to synthesize Drug-Linker Conjugates for ADC. Especially for the synthesis of Deruxtecan (HY-13631E), a toxic drug-linker conjugate.