Lomustine is an alkylating nitrosourea compound used in chemotherapy. Lomustine (420 μM) triggers apoptosis through the mitochondrial pathway via decrease in the level of the anti-apoptosis proteins Bcl-2 and Bcl-xl, respectively, in both medulloblastoma and normal human epithelial and fibroblast cells. Lomustine induces cell cycle delay in G2/M phase in medulloblastoma cells and up-regulates p21 protein level in a p53-independent manner in HFSN1 cells.