Even if patients lack property rights in their tissues, they do have a common law right against battery that would preclude investigators from removing tissue from their bodies and using it without their consent. Individuals may therefore demand payment for permission to remove their tissues, as in the current markets for blood, blood products, oocytes, and sperm (6-7). A striking case was that of Ted Slavin, a man with hemophilia who contracted hepatitis B and then developed extremely high titers of hepatitis B antibodies in his serum. When his physician informed him that his blood might be valuable to medical researchers, he was able to sell his serum for as much as $10,000 per liter, providing himself with a source of revenue for the rest of his life (8).