MUC1 and breast carcinoma: In addition to these short cancer-associated antigens, MUC1 expressed by breast carcinoma cells also carries the mono- and disialyl core 1 structure (ST, NeuAcα2-3Galβ1–3[NeuAcα2–6]+/–GalNAcα1-O-Ser/Thr) found widely in normal cells [24–26].