ALDH2 and central nervous system cancer: In the LGG cohort from the TCGA dataset, ALDHs including ALDH2, ALDH6A1, ALDH5A1, ALDH9A1, ALDH1A1 were upregulated in WHO grade II gliomas while the increased expression of ALDH16A1, ALDH3B1, ALDH3A2, ALDH1A2, ALDH3A1 was found in WHO III grade gliomas (Supplementary Figure 1A).