Sensitivity of rat and human-derived CNS cells and human cancer cells to BCNU or cisplatin. Cells were treated with (a,c,e,g) cisplatin and (b,d,f,h) BCNU over a wide dose range (0.1–100 μM and 5–200 μM, respectively). Each experiment was carried out in quadruplicate and repeated multiple times in independent experiments. Data represents mean of survival ± SEM, normalized to control values. There are no concentrations of either drug for which tumor cell lines were more sensitive than the more sensitive neural progenitor cells and oligodendrocytes.