Genetic and epigenetic aberrations include abnormal methylation, microRNA changes, abnormal DNA, discoloration and structural changes, DNA methylation (particularly O6-methylguanine-DNA methyltransferase (MGMT) methylation), and histone modifications (methylation, acetylation, phosphorylation, and other modifications) that play a pivotal role in the progression of GBM. The gene discussed is MGMT; the disease is glioblastoma.