CD79A and cancer: Second, IgA, the major O-glycosylated protein in serum is not bound by galectin-1 [25], and third the major cancer associated O-glycans, the T antigen (Galβ1-3GalNAcα) and Tn-antigen (GalNAcα) are poor ligands to human galectin-1[35], [55].