The molecular epidemiology of growth signal transduction proteins.

Cellular proteins involved in growth signal transduction pathways represent potential molecular epidemiologic biomarkers for various disease processes of toxicologic interest, particularly cancer. In many instances, the proteins gain access to the extracellular environment and thus can be detected in easily accessible biological fluids such as serum or plasma. This paper reviews the experience with selected examples of such proteins, including growth factors, growth factor receptors, G proteins, and nuclear DNA-binding proteins, as serum or plasma biomarkers of disease.