Reviewers scored the T2-FLAIR mismatch sign as being present in 34 of 70 diffuse astrocytoma tumors, four of five anaplastic astrocytoma tumors and 0 of 79 diffuse oligodendroglioma, anaplastic oligodendroglioma and IDH-WT tumors, making the specificity of this study 100% for differentiating astrocytomas from other LGGs [43]. The gene discussed is IDH1; the disease is anaplastic oligodendroglioma.