Regarding the relationship between HIF1α and Sox2/Klf4, previous studies have suggested that HIF1α upregulates Sox2 in GBM26 and Klf4 in mesenchymal stromal cells (MSCs)27 or colon cancer24; however, few reports have analysed the correlation between HIF1α and Klf4 in GBM. The gene discussed is SOX2; the disease is glioblastoma.