Food factors may be effective chemopreventive agents if they have a significant impact on a "valid" cellular or molecular target. Specific criteria can determine whether a molecule is a "valid" target for cancer prevention. MAP kinase signal transduction pathways meet these criteria and are "valid" targets for chemoprevention. Certain food factors, including EGCG, theaflavins, and resveratrol, specifically target these pathways and result in significant anticancer effect. Whether consumption of a diet rich in EGCG, theaflavins, or resveratrol can have an anticancer effect in humans remains to be determined. One of the major challenges in conquering cancer is in the area of translational research. Rapid and efficient mechanisms for moving promising compounds from the "bench to the clinic" are desperately needed.