TNF and squamous cell intraepithelial neoplasia: The incidence and cumulative incidence rate of each outcome (HPV persistence, HPV clearance, SIL incidence, SIL persistence, SIL progression) will be determined, adjusting for changing levels of the immune biomarkers IL-10, IL-4, TGFβ1, IFNγ, IL-6, and TNFα and the expression levels of E6 and E7 in the cervix.