Overexpression of Nanog has been reported by several groups in germ cell tumors, as well as other tumors, including breast, cervix, oral, kidney, prostate, lung, gastric, brain and ovarian cancer [7,8,9,10,11,12,13,14,15,16,17,18,19], though Schreiber and colleagues suggested that transcription of Nanog and Oct4 is unlikely to be a key determinant of CSCs properties [20]. Here, NANOG is linked to germ cell tumor.