CD4 and cervical squamous intraepithelial neoplasia: In the present study, we find that the PD-1/PD-L1 pathway is upregulated in CIN patients, and the levels of TGF-β and IL-10 are elevated, consistent with the results by Yang et al. Further study shows that PD-1 expression on the surface of CD4+T and CD8+T cells, PD-L1 expression on DC surface, and mRNA expression of PD-1 and PD-L1 are significantly enhanced in cervical cancer patients, being higher than that in CIN group.