A number of studies have therefore demonstrated that p16INK4A protein over-expression may serve as a surrogate biomarker for biologically and clinically relevant high risk HPV infection in squamous cell carcinoma of the conjunctiva, as well as squamous cell carcinoma and glandular epithelial dysplasia of the uterine cervix [44,45]. Here, CDKN2A is linked to squamous cell carcinoma.