NANOG and neoplasm: The self-renewal and differentiation process in CSCs are mainly regulated through transcriptional regulators (such as OCT4, Nanog, YAP/TAZ, and Myc), as well as signaling pathways (such as Wnt, Notch, HH, TGF-β, PI3K/Akt, EGFR, and JAK/STAT), thereby being able to produce, expand, and maintain more CSCs populations, as well as all the non-CSC progeny in a tumor [10,11].