The TALE-TF system has successfully been employed to activate Sox2 and Klf4 genes in HEK293 cancer cell line.70 TALEs genome-editing system has also been used for reactivation of the Oct4 gene.71 Designed TALEs efficiently upregulated Oct4 transcription in ESCs, but failed to activate this gene in ESC-derived neural stem cells (NSCs) because of the repressive epigenetic state of the corresponding genomic locus. Here, POU5F1 is linked to cancer.