Sensitivity of GSC lines to TMZ as single agent. Panel A. Chemosensitivity of GSC and GBM cell lines. Tumor growth was evaluated 7 days after drug exposure. Data were plotted in 4 different graphs which gather GSC lines with TMZ IC50s >300 μM (#23, #83, #1, #61, #30), with TMZ IC50s comprised between 200 and 300 μM (#148, #62), with TMZ IC50 < 100 μM (#74, #28, #144) and the two GBM cell lines (SJGBM-2, U87). The results are expressed as survival fraction and are the mean (± SD) of three independent experiments. Panel B. Doubling times of GSC and GBM cell lines. Data are the mean (±SD) of three independent determinations.