SOX2 deletion in zygotes triggers differentiation of ESCs into trophectoderm (TE)-like cells, leading to failure in embryoblast formation and early embryonic lethality.3 The most attractive feature of SOX2 is being one of the Yamanaka factors, whose ectopic expression along with Oct4, Klf4, and c-Myc converts mouse embryonic fibroblasts into induced pluripotent stem cells (iPSCs).4 Following the discovery of the key roles of SOX2 in ESCs and iPSCs, SOX2 expression in human cancers has been widely investigated. Here, SOX2 is linked to cancer.