As Sox2 has not only been described to be involved in tumour formation itself but also in damage-induced reactions of the CNS, like reactive processes evoked by non-neuroepithelial CNS tumours50 and penetrating stab wounds51,52, we also examined the expression of Sox2 in relation to the CNS tissue markers GFAP and Olig2. This evidence concerns the gene OLIG2 and neoplasm.