MUC1 (UniProt ID P15941) synthetic glycopeptide fragment (Pro126-Gly149; UniProt position 126-149, aa length 24) from the tandem repeat (TR) region of the MUC1 protein. The fragment contains tumor-associated carbohydrate antigen (TACA), Tn-antigen, O-glycosylation (α-GalNAc) at Ser130 and Thr131. The C-terminus is carboxylic acid.