SOX2 and cervical carcinoma: While80% of CIN III or CSCC expressed Sox2 protein, compared with only 25% of normal cervix, CSCC grades II and III showed relatively higher intensity of SOX2 staining compared with that of squamous carcinoma I. Also, SOX2 was strongly expressed in primary tumorspheres derived from fresh cervical cancer tissues, but was never or seldom detected in differentiated cells.