MUC1 and breast cancer: While it was noted that different types of breast cancer each had different aberrations [for instance, purified MUC1 from T47D breast cancer cell lines has primarily core 1 type O-glycans, while MUC1 from MCF-7 is composed of core 2 type O-glycans (Muller and Hanisch, 2002)], all breast cancer cell lines displayed an increased number of carbohydrates per glycoprotein when compared with healthy cells.