Exelixis Inc. is a leader in the fields of model system genetics andcomparative genomics. These fields involve the systematic study of simpleorganisms, such as fruit flies, nematodes, mice, zebrafish and simple plants, to rapidly and efficiently determine gene function and establish its commercial utility in humans and other commercially important biological systems. The proprietary technologies provide a rapid, efficient and cost-effective way to move beyond DNA sequence data to understand the function of genes and the proteins that they encode.