In cervical neoplasia and cancer, CD8+ T cell reactivity to E6 peptides appears to be dominant across all disease grades, inferring that E6-specific CD8+ T cells are not vitally involved in HPV clearance, whereas frequency of CD4+ responders is far lower among those with progressive disease, indicating the importance of CD4+ T-cell response for HPV clearance [87]. This evidence concerns the gene CD4 and cancer.