By studying cytological changes in the squamous epithelium of the cervix, a significantly higher expression of p16 in invasive carcinoma was demonstrated compared to expression in low and high squamous intraepithelial dysplastics lesions, and it was suggested that this marker could be used to differentiate noninvasive from invasive cervical changes [52,53]. This evidence concerns the gene CDKN2A and invasive carcinoma.