TNF and cervical squamous intraepithelial neoplasia: To assess the roles of NK cells and these inhibitory receptors in the immunopathogenesis of HPV16(+) CIN, we examined the subset distribution, Interferon-γ (IFN-γ) and Tumor necrosis factor-α (TNF-α) expression levels and inhibitory immunophenotype expression levels of peripheral blood NK cells from HPV16(+) women with different CIN grades or HPV(−) women.