To select candidate metabolites related to enhanced 5-ALA fluorescence in IDH1 mutant malignant glioma cells, we identified three metabolites (citrate, ɑ-KG, and 2-HG) of which the levels were significantly altered in U87MG-IDH1R132H cells after 5-ALA treatment (Figure 4). This evidence concerns the gene IDH1 and glioma.