SOX2 and cervical cancer: Together, these findings reveal that Piwil2, whose expression is restored by the combination of E6 and E7 in cervical cancer, may reactivate the “core” somatic cell reprogramming factors c-Myc, Nanog, Oct4, Sox2, and Klf4 by regulating the shift of acetylation and trimethylation of H3K9, thus initiating cell reprogramming and contributing to TIC formation (Figure 8).