SOX2 and neoplasm: Moreover, NCT-503 treatment led to a decrease in the number of tumor cells expressing the stem cell markers SOX2 and Olig2 (Fig. 6N and Supplementary Figure S8E), an increase in the expression of markers associated with DNA repair (Fig. 6O and Supplementary Figure S8F), and an increase in tumor cell apoptosis (Supplementary Figure S8G).