Comparison II (IDH1-mut astrocytoma [n = 26] versus IDH1-WT astrocytoma [n = 9]) (Figure 1A) identified sn-glycero-3-phosphocholine, hypoxanthine, betaine, and 2-HG as differentiating metabolites with P < 0.05 and fold change > 1.2 (Tables 1 and 2) and 16 PLS-DA variables (2-HG, cystathionine, sn-glycero-3-phosphocholine, betaine, histamine, 2-hydroxybutyrate, valine, hypoxanthine, ADP, and o-phosphocholine) with a VIP score > 1 (Figure 3A). The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).