TP53 and glioblastoma: Although we did observe apoptosis and necrosis induction after metformin treatment, this was not restricted to those lines with mutated TP53. GBM cell metabolism is clearly influenced by multiple genes, which may be differentially mutated in the different lines tested, and which may explain how the particular metabolic weakness due to mutated TP53 in LN229 may be overridden by other characteristics, and conversely, how other genes contribute to metformin sensitivity in TP53 WT cell lines.