When studying the topographical distribution of these two markers in squamous and glandular preneoplastic lesions (SIL and adenocarcinoma in situ; AIS), we noted an almost exclusive expression of SOX2 in SIL and a more complex, combined SOX2 and SOX17 expression pattern in AIS. The gene discussed is SOX17; the disease is squamous cell intraepithelial neoplasia.