MYC and neoplasm: Mouse embryonic fibroblasts (MEF) overexpressing Myc/Ras developed into tumors when implanted in the hind limb of mice, whereas mice implanted with SIRT3+/+ Myc/Ras, SIRT3−/− Myc, or SIRT3−/− Ras MEFs did not, thus asserting tumor suppressor activity of SIRT3 [11].