FOXO1 and central nervous system cancer: According to two other studies which proposed FOXO1 as an oncogene, two hypotheses can be raised; a) FOXO1 can act as an oncogene in radioresistant or chemoresistant glioma cell lines that have not responded to conventional treatments [152], and b) in a context-dependent manner FOXO1 can act as an oncogene by increasing stem cell markers in glioma [137] (Fig. 5B).