For example, 2-oxoglutarate was predicted to be significantly affected by COL6A3 mutation in CNS-GBM/Oligo at a genome scale (in the step 2), but no such significance was observed between 2-oxoglutarate and COL6A3 mutation at individual 2-oxoglutarate biosynthetic pathways, including alanine and aspartate metabolism; citric acid cycle; glutamate metabolism; glycine, serine, alanine and threonine metabolism; urea cycle; transport reactions; and additional unassigned reactions. Here, COL6A3 is linked to glioblastoma.