MUC1, a single-pass, type 1 transmembrane glycoprotein that is expressed only on the apical surfaces of normal glandular and ductal epithelial cells [22, 23], has been shown to be a potential target for cancer therapy, ranking as the 2nd cancer vaccine target among 75 other cancer antigens assessed by the National Cancer Institute [24]. This evidence concerns the gene MUC1 and cancer.