KLF4 and glioblastoma: This review aimed to provide a perspective on CSC markers SALL4, OCT-4, SOX2, STAT3, NANOG, c-Myc, KLF4, CD133, CD44, nestin, and Glial fibrillary acidic protein (GFAP) reported in GBM, and attempt to place these markers in the context of the GBM CSC hierarchy, from the most primitive ESC markers to the more mature.