FAS and cancer: Taken together, women with early neoplastic lesions of the cervix, such as carcinoma in situ and microinvasive carcinoma, displayed a coordinated increase in expression of markers of regulatory T cells in blood CD4+/CD8+ lymphocytes, along with more pronounced cross-relationships between Treg numbers, CD95 expression on CD4+/CD8+ T cells, and apoptosis, with these interrelated changes being suggestive of the mechanisms responsible for the development of systemic immunological deficiency throughout cervical cancer progression.