- Disturbed expression of ribonucleotide reductase and cytokeratin polypeptides in focal epithelial hyperplasia. An immunohistochemical study using monoclonal antibodies. Rozell, B., Stenman, G., Magnusson, B., Lekholm, U., Nagle, R.B., Hansson, H.A. J. Oral Pathol. (1986)