In breast cancer models, statins blocked tumor growth by: 1) inducing cell cycle arrest by cyclin D1-CDK4; 2) decreasing cell proliferation through inhibiting prenylation and activation Rho/Ras family of proteins; 3) modulating pro- and anti-apoptotic proteins such as Bcl2 and Bax, and by inducing reactive oxygen species (ROS) (202), and 4) contributing to oxidative stress by inhibiting coenzyme Q synthesis (206). Here, CDK4 is linked to neoplasm.