There are a number of stemness-related transcription factors, such as Nanog (nanog homeobox), Oct4 (octamer binding transcription factor 4) and Sox2 (sex determining region Y-related high mobility group box 2), which are activated in both embryonic and cancer stem cells and comprise a core regulatory network for stem cell self-renew and pluripotency maintenance [30]. Here, SOX2 is linked to cancer.