A network of core transcription factors (TFs) including OCT4, NANOG, KLF4, LIN28 and SOX2 promote the undifferentiated state of both hESC and human embryonal carcinoma cells (hEC) via inducing and sustaining expression of stem cell related genes and simultaneously suppressing expression of somatic enriched genes. This evidence concerns the gene POU5F1 and embryonal carcinoma.