Nuclear expression of Ki67 was limited to the lower squamous layers (score 1+) in 4/4 cases with immature metaplasia and 8/10 cases with L-SIL; the remaining 2/10 L-SIL cases showed Ki67 expression extended to the intermediate epithelial layers (score 2+). The gene discussed is MKI67; the disease is squamous cell intraepithelial neoplasia.