ISG15 and central nervous system cancer: Some IFN‐stimulated genes (ISGs), such as FASLG, TNFSF10, and ISG15, were reported to have effects on cancer stem cell formation.39, 40, 41 GAS5 was also reported to control human embryonic stem cell self‐renewal34 and suppress malignancy of human glioma stem cells.42 Effects of GAS5 on cancer stem cell may need further illustrations, including those on esophageal cancer.