Figure 1. Dose-dependent lithium toxicity in vitro.

A. Dose-response curve for lithium toxicity showing that the neural multipotent stem/progenitor cell line C17.2 is far more resistant to lithium toxicity than 7 different paediatric malignant brain tumour cell lines (72 h). B. A bar graph showing the IC₅₀ and 95% confidence interval values of lithium for the 8 different cell lines. The IC₅₀ of the neural multipotent progenitor cell line is 2.7-8.1 times higher than that of the tumour cell lines. C. The effect of lithium and irradiation on cell survival of DAOY cells, demonstrating that lithium has no protective effect against irradiation. ** p < 0.01, *** p < 0.001.