Unexpectedly, a significant increase in the average copy number of genes tested by Oncomine located on 19p (STK11, GNA11, MAP2K2, and JAK3) was detected in IDH-wildtype infiltrating astrocytoma (average CN = 2.44 ± 0.39) compared to IDH-mutant infiltrating astrocytoma (average CN = 2.22 ± 0.29; p = 0.002; Fig. 2a) and oligodendroglioma (average CN = 2.22 ± 0.13; p = 9.96 × 10–5; Fig. 2a). Here, IDH2 is linked to oligodendroglioma.