Because the action of G47∆ does not theoretically depend on the genetic background of tumor cells, and testing for isocitrate dehydrogenase 1 (IDH1) mutation was not regularly performed in 2014 when this trial protocol was submitted to the Japanese Pharmaceuticals and Medical Devices Agency (PMDA), the status of IDH1 mutation was not included as a covariate of this study. This evidence concerns the gene IDH1 and neoplasm.