KLF4 and neoplasm: The pluripotency transcription factors OCT3/4, SOX2, KLF4, and c-MYC (OSKM) result downregulated upon miRNA cluster induction and, together with POU3F2, SALL2 and OLIG2, are required for the maintenance of glioblastoma stem-like tumor propagating cells (Yang et al., 2015) (Figure 2).