IDH1 and glioblastoma: Among those that clustered with IDH-wildtype glioblastoma, four of the six tumors were with the mesenchymal subclass (all of which had co-occurring CDKN2A homozygous deletion but only one with co-occurring ATRX mutation), one was with the MYCN subclass (which had focal high level MYCN amplification), and the remaining one was with the midline subclass (which had truncating SETD2 mutation).