SOX2 and cervical cancer: Then, SOX2-positive and SOX2-negative cervical cancer cells were isolated by pSOX2/EGFP plasmid using FACS technology in cervical cancer cell lines, such as SiHa and C33A, and confirmed that SOX2-positive subpopulation cells exhibited dominant characteristics of CSCs, including tumorigenicity, self-renewal and differentiation (Fig 1B and 1C).