Extracted DNA from two FFPE glioma samples, IDH1 p.R132H with VAF of 39.5% and IDH2 p.R172K with VAF 48.9% (Sample 22), were diluted with DNA extracted from IDH1/2 wild-type FFPE glioma sample (Supplementary Table 3). Here, IDH1 is linked to central nervous system cancer.