The antitumour activity of TMZ has been demonstrated in a variety of MGMT-deficient tumours; including glioblastomas, gastroenteropancreatic neuroendocrine tumours and phaeochromocytomas/paragangliomas.12 16 22 The aim of the current study was to determine if MGMT methylation status could identify a subgroup of patients with GIST that may benefit most from TMZ therapy and to analyse potential correlations between molecular drivers of GIST, clinical and pathological parameters and MGMT methylation status. This evidence concerns the gene MGMT and gastrointestinal stromal tumor.