TP53 and cervical squamous intraepithelial neoplasia: In the past, pioneering morphological, and molecular studies allowed to disclose the chain of events underlying the “adenoma to carcinoma cascade” theorized by Fearon and Vogelstein characterized by chromosomal instability (CIN) and sequential mutations of Adenomatous Polyposis Coli (APC), Kirsten rat sarcoma viral oncogene homolog (KRAS), and tumor protein p53 (TP53) genes (5).