{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"SRY (sex determining region Y)-box 2, also known as SOX2, is a transcription factor that is essential for maintaining self-renewal, or pluripotency, of undifferentiated embryonic stem cells. It is required for stem cell maintenance in the central nervous system, and it also regulates gene expression in the stomach."}]},{"type":"paragraph","children":[{"type":"text","value":"SOX2 is expressed in fetal brain and is used as a marker for multipotential neural stem cells. In tumors, SOX2 expression is observed in teratoma of the central nervous system, melanoma, testicular germ cell tumor, cervical carcinoma, lung cancer, breast cancer with basal cell phenotype, and squamous cell carcinoma of the gastrointestinal tract. SOX2 may be useful in the identification of embryonal carcinoma. In stage I lung adenocarcinomas, SOX2 seems to be an independent predictor of poor outcome and may help stratify patients at increased risk for recurrence."}]}]}