CIN is characterized by the inactivation of tumor-suppressor genes, as tumor protein p53 (TP53) and adenomatous polyposis coli (APC), activation of oncogenes, as KRAS and B-raf proto-oncogene (BRAF), and LOH of long arm of chromosome 18. Here, TP53 is linked to cervical squamous intraepithelial neoplasia.