CD4 and cervical squamous intraepithelial neoplasia: The percentages of CD4+PD-1+ T cells, CD8+PD-1+ T cells, or CD4+CD25+PD-1+ Treg cells were significantly different among normal control group, CIN group, and cervical cancer group (P < 0.05 for all) (Figures 1(a)–1(e)).