RESUMEN
Last decade has witnessed increased interest in studies dealing with molecular markers of health and disease expression of genes. Specific toxicant "signatures" have been detected using genome base technologies such as microarrays. Further toxins have been classified on the basis of these signatures. Knowledge on these signatures has helped in the identification of novel drug candidates. This review discusses the gene expression studies recently made on arsenic, cadmium, mercury, chromium, lead, copper, nickel, manganese, and other essential elements. Toxicogenomics standards and their organizations have also been briefly described. Although this information can not be considered as complete, recent reports from different laboratories on bacteria, fish, laboratory animals and humans have been summarized. It is expected that toxicogenomics data presented in this review will be helpful in planning and excretion of human health risk assessment programs.