Recent studies show that TLX plays an essential role in the development of brain tumors, as evidenced by its upregulation in high-grade gliomas and its transgenic overexpression can result in a long-term expansion of a subgroup of NSCs and form gliomas in mutant mouse brain in conjunction with genetic loss of tumor suppressors Pten or p53 [25–27]. The gene discussed is PTEN; the disease is glioma.