CHEK2 and glioblastoma: In addition, 71 of 378 ES enriched genes were SOX2 targets in GBM cells including CDC20 (cell division cycle 20 homolog of S. cerevisiae), CHEK2 (CHK2 checkpoint homolog of S. pombe), FGF13 (fibroblast growth factor 13), RFC3 [replication factor C (activator 1) 3, 38 kDa] and UTF1 (undifferentiated embryonic cell transcription factor 1) (Additional File 6).