NANOG and neoplasm: Overexpression of many transcription factors such as SRY-Box Transcription Factor 2 (SOX2), octamer-binding transcription factor 4 (OCT4), B lymphoma Mo-MLV insertion region 1 homolog (BMI1), and Nanog Homeobox protein (NANOG) have been identified as key players in CSCs-related tumor initiation and metastasis formation.