p16 expression in the squamous cervical epithelium is encountered in dysplastic, HPV related lesions: Low grade squamous intraepithelial lesion (L-SIL, CIN1) and high grade squamous intraepithelial lesion (H-SIL, CIN2-3); on the other hand, p16 is usually absent in normal squamous epithelium as well as in inflammatory conditions and in the metaplastic squamous epithelium [3,5,13,14,15]. This evidence concerns the gene CDKN2A and squamous cell intraepithelial neoplasia.