In the validation cohorts, lower expressions of ALDH1A1, ALDH6A1, ALDH2, ALDH5A1 were observed in GBM compared to LGG, while ALDH16A1, ALDH3B1 and ALDH3A1 were preferentially enriched in GBM (Figures 1B–D). Here, ALDH3B1 is linked to glioblastoma.