We strongly recommend to apply these markers in cases where routine microscopy work-up may suggest an IDH1 wildtype glioma in a child with focal seizures and a difficult-to-classify histomorphological lesion, neither fitting into the group of hypercellular glio-neuronal neoplasia nor focal cortical dysplasia, in particular when presenting in the temporal lobe. This evidence concerns the gene IDH1 and central nervous system cancer.