To assess EMX2 mRNA expression level, we focused on a previously reported transcriptome gene signature associated with GB intratumor heterogeneity (published by Aubry et al. [10] We observed a significant decrease of EMX2 expression in GB tumor and necrotic zones compared to paired interface and peripheral brain zones derived from the same patients (n = 10) (Fig. 2a). The gene discussed is EMX2; the disease is neoplasm.