<p>Anal histology identified by a trained pathologist for each time point (25 mice/group) following treatment with and without DMBA (0.12μmole topically to anus weekly). There is a statiscally significant increase in anal dysplasia over the time course of DMBA treatment, with the majority of the mice at 5 and 10 weeks of DMBA treatment having low-grade dysplasia, while 75% of mice at 15 weeks. By 20 weeks of DMBA treatment 100% of K14E6/E7 mice have overt carcinoma. During this same time course none of the K14E6/E7 mice not treated with DMBA developed anal cancer.</p