MUC1 and cancer: Consequently, SN-101 (IgG1) is the first antibody among anti-MUC1 mAbs selectively recognising cancer-relevant Tn-glycosylated MUC1 fragments screened by our approach that enables precise analyses of the crystal structures of Fab and its complex with a target MUC1 glycopeptidic neoepitope (ESI Fig. S1†).