FOXO1 and breast cancer: Some oncogenic factors have been shown to control NAMPT expression and activity, such as the oncogenic transcription factor EWS-FLI1 in Ewing’s sarcoma and the tumor suppressors FOXO1 (negatively controlling expression of NAMPT) as well as AKT (positively controlling NAMPT expression) in breast cancer (Mutz et al., 2017; Jeong et al., 2019).