Embryonic stem cells have the ability to develop into virtually any cell in the body, and they may have the potential to treat medical conditions such as diabetes and Parkinson's disease. In August 2001, President Bush announced that for the first time, federal funds would be used to support research on human embryonic stem cells, but funding would be limited to "existing stem cell lines." NIH has established a registry of 78 human embryonic stem cell lines that are eligible for use in federally funded research, but only 21 cell lines are currently available. Scientists are concerned about the quality and longevity of these 21 stem cell lines. NIH Director Elias Zerhouni stated before a Senate subcommittee in March 2007 that research advancement requires access to new human embryonic stem cell lines.