POU5F1 and cancer: Since neither full-length OCT4A transcripts nor full-length OCT4A proteins in somatic cancer cells have been identified or verified by unequivocal means (e.g., DNA sequencing, mass spectrometry (MS)) so far, what we can conclude from the literature was that certain POU5F1 transcripts or other POU family member transcripts may be expressed in somatic cancer cells and/or a subpopulation of cancer cells known as cancer stem cells (CSCs) or tumor initiating cells (TICs).