FOXO3a is a tumour suppressor could be regulated by several crucial pathways, including PTEN/PI3K/Akt [19, 48–50], ERK/MAPK [51], and IKK [52] signaling pathway and modulation of FOXO3a has been reported to involve in the regulation of CSC properties, chemosensitivity and tumour initiation in cancers [16, 19, 53]. Here, FOXO3 is linked to cancer.