Overexpression of MUC1 and the expression of aberrant forms of MUC1, typified by the loss of apical distribution, have been reported in many carcinomas (Zotter et al, 1988), in particular breast and ovarian (Apostolopoulos et al, 1999; Hu and Xing, 2003). The gene discussed is MUC1; the disease is carcinoma.