IDH1 and glioma: IDH1 MT glioma cell lines had a slightly lower IC50 for VPA compared to IDH1 WT cell lines (WTIC50 = 1.23; MTIC50 = 0.96), and the hill slope between the two dose–response curves were statistically significant (WTHill Slope = −0.80; MTHill Slope = −1.68; 0.0032) (Fig. 1A).