Our previous study showed that T2-FLAIR mismatch sign is only seen in a part of the non-enhancing IDH-mutant diffuse glioma cases at certain stages, and MRI techniques were able to further estimate the grading of astrocytomas with high accuracy.13 Many of the tumors likely lose T2 homogeneity as they grow in size, and become heterogenous. Here, IDH1 is linked to astrocytoma (excluding glioblastoma).