PTTG1 and neoplasm: As shown in Figure 7, both simvastatin treatment and PTTG1 knockdown significantly attenuated the expression of c-Myc, FGF-2, and cyclin D3 and increased p21 expression, implicating that simvastatin exerts anti-tumor effects through suppressing PTTG1 function in MDA-MB-231 cells.