The overall objective of the Caenorhabditis Genetics Center (CGC) is to promote research on the small metazoan Caenorhabditis elegans by acquiring, maintaining, and distributing genetically characterized nematode stocks. Researchers throughout the world use genetic stocks obtained from the CGC in diverse basic and applied research endeavors. Studies using this premier model organism have led to fundamental insights into basic biological mechanisms, including the genetic basis of programmed cell death, the discovery of microRNAs, and the mechanism of RNA interference in animals. The nematode has also proved important for understanding mechanisms of cancer progression and other diseases including Alzheimer's and Parkinson's, as well as for revealing basic mechanisms underlying human development. In addition, C. elegans serves as a key model for illuminating our understanding of parasitic nematodes with relevance to human and livestock health. As the sole general stock center for the nematode C. elegans, the CGC is an extremely important international research resource. The high demand for CGC strains reflects their great importance to the research community; currently more than 25,000 strains are distributed per year. The CGC curates C. elegans strains and distributes them upon request through an on-line ordering system. A new research component will be implemented to expand the activities of the CGC. The C. elegans genetic tool-kit will be enhanced through the generation of genetic tools to aid researchers in manipulations of lethal and sterile mutations.