p16

p16, also known as the "mitotic suppressor," is one of the cell cycle regulatory proteins. The overexpression of p16 indicates that normal cells are in the cell cycle arrest phase. Short time HPV infection does not affect the regulation of cell cycle, while persistent HPV infection cells show abnormal proliferation, resulting in p16 overexpression. Normal cervical epithelium almost does not express p16, so p16 overexpression can be used as a marker of cervical lesions, and in grading of cervical epithelioma-like lesions.