Cyclin E staining was nuclear in distribution, and the frequency of positive staining, ie., moderate or strong intensity, was significantly higher (P < .001 for cyclin E staining vs. diagnosis) in all of the lesional epithelia (92.3, 51.6, and 50% of low-grade and high-grade SILs and carcinomas, respectively) compared with nonlesional epithelium (5.9%).