SOX2 and renal cell carcinoma: Using sphere formation assays to evaluate the CSC formation, we found knocking down AR (sh-AR) using two different sequences both increased the CSC formation (Fig. 1C) as well as the expression of CSCs biomarkers including CD24, CD133, PAX2, SOX2 and CD105 in RCC SW839 cells under hypoxia condition (Fig. 1D).