IDH1 and glioblastoma: Conspicuously, the glioblastoma cell line had a characteristically low level of the expression all of the genes that were tested except LCK. Remarkably, the mRNA level for the IDH1 transcription was also the lowest among all of the cell lines that were investigated, which correlates well with the low basal level of IDH1 or the IDH1 R132H mutant in those U-251 cells, which was previously reported by Oizel et al. [62] This also explains the relative resistance of glioblastoma cells to both the tosylamides and two other inhibitors.