IDH1 and oligodendroglioma: In our WGS analysis, the primary and relapsed tumors from both cases carried the typical IDH1 p.R132H mutation (chr2:208,248,388:G>A, VAF Case 1: 0.33 and 0.33, Case 2: 0.23 and 0.40 for primary and relapsed samples, respectively) and whole chromosome arm losses of 1p and 19q, thus confirming the oligodendroglioma diagnosis.