Paul R. Billings is chief medical officer and deputy network director of the Heart of Texas Veterans Integrated Service Network. In addition to his M.D., he holds a Ph.D. in immunology from Harvard University. An expert on genetic diseases who has helped develop legislation on genetic discrimination, he is the author of DNA on Trial: Genetic Information and Criminal Justice and was a presenter at the 1998 Sigma Xi dress: Heart of Texas Veterans Healthcare Network, 1901 N. Highway 360, Suite 350, Grand Prairie TX 75050 Internet: paul.billings@med.va.gov.