Analyzing the metabolite concentration in a subset of the screened 38 patients, the median value of total 2HG and D-2HG serum concentration was 5.6 ± 1.3 μmol/L and 5.3 ± 1.2 μmol/L in patients with an IDH1-mutated tumor and 1.0 ± 0.2 μmol/L and 0.6 ± 0.1 μmol/L in patients with an IDH1 wild-type tumor, respectively (p = 0.0008 and p = 0.0006; Figure 3). The gene discussed is IDH1; the disease is neoplasm.