DOE chose this organism for DNA sequencing because of its potential usefulness in cleaning up waste sites containing radiation and toxic chemicals. Its DNA sequence was completely determined in 1999, and scientists now are exploring ways to add genes from other organisms to expand D. radiodurans’ capabilities for removing toxic wastes from contaminated sites. The added genes encode proteins that transform heavy metals to a more benign biomass and allow the concentration of heavy metals and the breakdown of organic solvents such as toluene. Studies into this organism’s remarkable DNA-repair pathways also may help scientists better understand how defects in human cellular processes might lead to the development of cancers.