FMOC-L-THR (AZP-531) is an analogue of unacylated ghrelin designed to improve glycaemic control and reduce weight. The O-glycosidic linkage and the O-acetyl protection in this building block is stable to both piperidine and TFA, making it completely compatible with standard protocols in Fmoc solid phase peptide synthesis. The Tn antigen is a tumor-associated carbohydrate antigen that is not normally expressed in peripheral tissues or blood cells. Expression of this antigen, which is found in a majority of human carcinomas of all types, arises from a blockage in the normal O-glycosylation pathway in which glycans are extended from the common precursor GalNAcα1-O-Ser/Thr (Tn +antigen)[1].