IDH1 and astrocytoma (excluding glioblastoma): The average copy number for genes tested by the Oncomine panel located on chromosome 1p (MTOR, MYCL, MPL, MAGOH, JAK1, and NRAS) was significantly lower in cases of oligodendroglioma (average CN = 1.15 ± 0.14) compared to IDH-mutant infiltrating astrocytoma (average CN = 2.04 ± 0.37; p = 3.65 × 10–13) and IDH-wild type infiltrating astrocytoma (average CN = 1.97 ± 0.16; p = 1.76 × 10–12) but no significant difference was detected between IDH-mutant and IDH-wildtype infiltrating astrocytoma (p > 0.05; Fig. 2a).