Fig. 1

A MUC1 belongs to mucin family and its role in normal cells is protection of beneath cells from physical damages. In contrast, MUC1 play a different and complicated role in cancer cells. MUC1 cytoplasmic domain has crosstalk with other molecules like STAT1, HIFα and so on. These molecules are involved in growth, proliferation, angiogenesis, migration, invasion and metastasis. Because MUC1 has interaction with aforementioned molecules, it is a potential target in cancer therapy. B As illustrated above, MUC1 is hyper-glycosylated in normal cells. The tandem repeat, the black part including the APDTRRPAD amino acid sequence, is under the carbohydrate and consequently hided. C In cancer cells not only there is less carbohydrate density, but also new carbohydrates appear. Meanwhile, tandem repeat which was under carbohydrates before, becomes exposed. Thus, it can be concluded that MUC1 has distinct structure in normal and cancer cells