It acts by alkylating O6-guanine, O2-thymine and O4-thymine, inducing mutations of certain oncogenes such as p53 and genes coding for caspase-9, platelet-derived growth factor receptor alpha (PDGFRα), CDKN2A and EGFR, all related to the genesis of glial tumours [31, 32]. This evidence concerns the gene PDGFRA and glioma.