FAS and in situ carcinoma: Collectively, analysis of immunophenotypic data on peripheral blood lymphocytes from patients with CIN3/ carcinoma in situ or microinvasive carcinoma of the cervix suggests that the mechanisms, by which Tregs can expand their suppressive influence on antitumor immune responses and impair the balance between effector cell subsets (including via potentiation of CD95-mediated apoptosis), and which were previously established mostly with the use of murine models or other experimental systems, play a relevant role in promoting early cervical cancer progression and spread in humans.