In this cervical biopsy, the dysplastic, disordered cells occupy less than 1/3 of the thickness of the epithelium, and the basal lamina is intact, so this is cervical intraepithelial neoplasia (CIN) I. Note the koilocytotic change in some cells, consistent with human papillomavirus (HPV) effect. [Image contributed by Dr. Ilan Hammel, Tel Aviv University]