A product of mevalonate proximal to isoprenoids is the source of both a necessary growth factor and an inhibitor of cell proliferation.

These studies demonstrate that mevalonate or the mevalonate phosphates play a number of regulatory roles in cellular proliferation. They are not only required for cell growth but are also a source of an inhibitor of cell growth. Endogenous concentrations of mevalonate and the mevalonate phosphates are thus critical determinants of cellular proliferation.