In some cases, oncogenic factors regulate expression and activity of NAMPT, such as in Ewing sarcoma, where the oncogenic transcription factor EWS-FLI1 has been shown to regulate NAMPT expression (49) and in breast cancer, where FOXO1, a tumor suppressor, negatively regulates the expression of NAMPT while AKT positively regulates it (117). This evidence concerns the gene AKT1 and breast carcinoma.