The Tuskegee Syphilis study is infamous due to the treatment of the African American men involved in it. They were lied to as to the nature of their disease and the lack of treatment they were receiving. Although the men agreed to participate in the study, the type of informed consent we have today was not applied. Even after penicillin was discovered to be an effective treatment for syphilis the "study" continued for another 25 years!
When the Public Health Service's study began in 1932 it sounded like it was to be helpful. The purported intention was to justify treatment for black men who had syphilis. But the men involved were not told they had syphilis; instead they were told they were being treated for "bad blood". It is specifically troubling that black men were the only ones involved. Papers were written about the untreated effects of syphilis as a result of the study. Decisions were made to follow the study participants until death, and they were left untreated even after penicillin became the accepted way to treat the disease. In 1969 the Centers for Disease Control, the American Medical Association, and the National Medical Association all officially supported continuing the study. It was not until the details were published in the media that the study itself was stopped, and class action lawsuits were filed to assist survivors and their families. The last study participant died in 2004.
This study is important when reading the story of Henrietta Lacks because in both cases informed consent was not obtained, and in both cases it was African Americans who were treated as less important than people of other races. Both cases led to improvement in how study participants' rights were maintained.