In one of the darkest chapters in medical ethics, the United States government ran an experiment from the 1930s to the 1970s in which it withheld treatment and medical information from rural African-American men suffering from syphilis. The public uproar generated by the Tuskegee Syphilis Study eventually resulted in regulations restricting government-supported research testing on humans. These regulations are called the “Common Rule,” and they are right now up for their first full update.