The human epithelial carcinoma antigen recognized by monoclonal antibody AE3 is expressed on a sulfoglycolipid in addition to neoplastic mucins

► We investigate the human cancer-associated antigen recognized by antibody AE3 using carbohydrate microarrays. ► We find that is expressed on glycolipid as well as on mucin-type glycoproteins. ► AE3 has strong selectivity for the carbohydrate moiety of the sulfoglycolipid SM1a. ► Assignment of a discrete carbohydrate sequence as a cancer-associated antigen opens the way to its exploration as a novel biomarker.