MGMT and central nervous system cancer: In cases of multifactorial disease such as cancers, as the complex causality of the disease unfolds, identification of an interaction between the causal factors might help clinicians to better understand the pathophysiology; Spiegl-Kreinecker et al. found a complex interaction between the rs2853669 polymorphism and the TERT promoter mutation status in patients with glioblastoma [37], while Vuong et al. demonstrated an interaction between TERT and O6-methylguanine-DNA methyltransferase in patients with glioma [38].