Amongwomen with oncogenic HPV, HIV-positive women with low CD4 cellcounts are more likely than either HIV-negative women orHIV-positive women with high CD4 cell counts to develop SIL [19].Data concerning the effect of highly active anti-retroviraltherapy on the natural history of HPV infections and cervicaldysplasia are mixed and further investigation is needed in thisarea. This evidence concerns the gene CD4 and squamous cell intraepithelial neoplasia.