MUC1 and neoplasm: As a result, antibodies with specificity for the tandemly repeated immunodominant epitope within the MUC1 ectodomain (e.g., HMFG2 or SM3 antibodies) bind preferentially to a number of tumour-associated glycoforms of this mucin, while the 5E5 antibody selectively binds to MUC1 that carries the Tn antigen at this position [53].