Global Genomic Approaches to the Study of Human Gene Function

The completion of the human genome project and the increasing availability of cDNAs to most genes made accessible the possibility of identifying the function of every gene. In contrast to most previous studies which typically examined one or a few human genes at a time for their biological effects, activity, or expression levels, new reagent sets and technological advances now allow large subsets or potentially even all human genes to be studied in a single experiment. Such high throughput approaches not only evaluate expression patterns of known genes, they may also be useful for assigning new activities to genes, placing them in signaling networks not previously known. Functional genomic studies that systematically manipulate either gene overexpression or gene knockdown via RNA interference are particularly useful for gaining global insights into gene function. Expansion of current genomic approaches to phenotypic and functional assays will likely provide new insights into the normal and pathological activities of many genes, undoubtedly accelerating the development of new therapeutic approaches for diagnosing, treating, and preventing disease.