MUC1 (UniProt ID P15941) synthetic glycopeptide fragment (Ala127-Pro146; UniProt position 127-146, aa length 20) from the tandem repeat (TR) region of the MUC1 protein. The fragment contains tumor-associated carbohydrate antigen (TACA), Core-3 antigen, O-glycosylation (GlcNAcβ1-3GalNAc) at Thr139 and Ser140. The C-terminus is an amide.