Thiomyristoyl is a potent and specific SIRT2 inhibitor with an IC₅₀ of 28 nM. IC50 & Target: IC50: 28 nM (SIRT2), 98 μM (SIRT1)^[1] In Vitro: Thiomyristoyl (TM) is a potent SIRT2-specific inhibitor with broad anticancer activity but little effect on non-cancerous cells. SIRT2-inhibition promotes c-Myc ubiquitination and degradation, suggesting the therapeutic potential of TM to target certain c-Myc-driven cancers. TM could inhibit SIRT2 with an IC₅₀ of 28 nM, but inhibits SIRT1 with an IC₅₀ value of 98 μM and does not inhibit SIRT3 even at 200 μM. TM inhibits three human breast cancer cell lines, MCF-7, MDA-MB-468, and MDA-MB-231^[1]. In Vivo: TM inhibits tumor growth in mouse models of breast cancer. TM does not cause significant toxicity in mice and no significant weight loss is observed in TM-treated mice. S5H, the acetyl-a-tubulin level is moderately but statistically significantly increased in tumors from TM-treated mice compared with those from vehicle-treated mice, suggesting that TM indeed inhibits SIRT2 in vivo^[1].