MUC1 and carcinoma: Abnormal O-glycosylation of mucins is a trait often shared by tumors.The Thomsen-nouveau (Tn) antigen, α-linked GalNAc carried onserine or threonine residues, is often found on mucin-type glycoproteinssuch as MUC1 at the surface of carcinoma cells.176 Because MUC1 is a tumor antigen, the capacity of Tn tobind human MGL has been used to increase TAA delivery to DCs.177−179 Tn-MUC1 glycoprotein was detected only in MHC II compartments,while a short Tn-MUC1 glycopeptide was found in both MHC I and MHCII compartments.