Since less than 2% of CD4/CD8 cells expressing CD25 molecule is observed in the normal endocervix [41] and since CD4/CD25 cells are recognised as regulatory T cells [13], the role of these cells in SIL development should be further evaluated performing longitudinal studies double staining CD4 and CD25. This evidence concerns the gene IL2RA and squamous cell intraepithelial neoplasia.