The MUC1 mucin is normally expressed in the epithelium of the fallopian tube, and its expression on the epithelium of the tubes with ectopic pregnancies has not been studied. The mean (+/- SEM) histologic score for MUC1 was 1.4 +/- 0.2 in the luminal epithelium of tubes with ectopic pregnancies, and the histologic score for normal tubes was 2.8 +/- 0.2; however, these findings must be confirmed with the identification of the cytoplasmic tail of MUC1.