For instance, monoamine oxidase B (MAO‐B) which is a target for the antidepressant deprenil and is localized almost exclusively in astrocytes (Riederer et al., 1987), has recently attracted attention because it can be used as an activator for pro‐drugs that, after the reaction with MAO‐B, become cytotoxic for glioma cells, which typically upregulate MAO‐B (Sharpe and Baskin, 2016). Here, MAOB is linked to central nervous system cancer.