MDH2 and glioblastoma: With the increase of risk score in GBM patients, the expression of the risky-type mRNAs (STC1, SRD5A3, MDH2, IL13RA1, TGFBI, and B3GAT3) was all upregulated gradually, while the expression of the protective-type mRNA (HDAC4, COG2, and G6PC2) was downregulated.