Drug sensitivity of CD133 positive cancer stem cells derived from No. 66. Both CD133 positive (CD133+) and CD133 negative (CD133-) tumor cells were collected from No. 66 by FACS sorting. 1 × 104 cells/well were plated in 96-well plate and treated with various concentrations of temozolomide, carboplatin, Taxol and VP16 for 48 hours in FBS/DMEM/F-12 medium. * indicates p < 0.05 compared to autologous CD133- cells. Data are representative of two independent experiments.