POU5F1 and neoplasm: 4-HPR was able to decrease the expression CD133 and ABCG-2 surface antigens as well as Oct-4 and Sox-2 gene expression in BTICs (Fig 5C, 5D and 5I–5L) and (Fig 5E, 5F, 5M and 5N), suggesting that 4-HPR targets the BTIC tumor component (Fig 5).