The expression of MAOB, IL4I1, ALDH3A2, WARS2, HAAO, AANAT, IDO1, OGDH, EHHADH, AOC1, INMT, HADHA, ALDH9A1, ALDH2, ECHS1, AADAT, ALDH1B1, CAT, HADH, GCDH, MAOA, IDO2, TPH1, and CYP1B1 was higher in glioma than normal brain tissue samples. The gene discussed is IDO1; the disease is glioma.