SIRT1 and Ewing sarcoma: Moreover, SIRT1 and LSD1 were reported to interact directly and thereby affect histone deacetylation and repress the genes regulated by the Notch signaling pathway (28), and in Ewing sarcoma, Notch signaling was found to be abrogated, and the restoration of Notch signaling by using SIRT1 inhibitors caused tumor-growth arrest (29).