ALDH2 and glioma: The results of IHC demonstrated that the expression level of KYNU was higher in high-grade glioma compared to low-grade glioma (Supplementary Figure S3A), and the expression level of ALDH2 was higher in low-grade glioma (Supplementary Figure S3B), confirming the results from sequencing that KYNU was hazardous factor and ALDH2 was protective factor.