The National Research Council and Institute of Medicine held a symposium to explore the health, policy, and ethical implications of direct-to-consumer genetic testing. In the third of four parts, participants focused on public understanding and use of genetic information. Among the issues they addressed were the availability of DNA and genome testing, privacy concerns for private persons and public figures, implementation of the Genetic Information Nondiscrimination Act, and ethical guidelines for use of genetic information. They responded to questions from the audience.