IDH2 and anaplastic oligodendroglioma: We selected six representative cases (i.e. two negative for SSTR2A expression, IRS = 0; two positive with low expression, IRS = 3; and two positive with high expression, IRS = 9) from anaplastic oligodendroglioma, IDH-mutant and 1p/19q-codeleted belonging to the group 3 and evaluated intratumoral heterogeneity of SSTR2A expression on whole tumor sample.