Chester Southam, a virologist at Sloan-Kettering Institute for Cancer Research, started to wonder if HeLa cells could infect the scientists handling them.
So he decided to test his theories by infecting a sick woman with Henrietta's cells (without the woman's consent, natch).
He did this to other patients and told them it was to test their immune systems, which was technically true if you're not worried much about ethics.
Southam watched the injection site to see if anything grew there. It did. He was able to remove the cancerous growths in all but four cases.
In those cases, the cancer returned. In one case, it metastasized.
Southam now needed healthy subjects to inject, so he recruited them from the Ohio State Penitentiary system (prisoners were considered a good pool for scientific research—a captive audience, you might say).
So Southam injected the men with HeLa cells. It turns out that healthy immune systems fought off the disease, and got more efficient at doing so with more injections.
Great observation, right? But Southam wound up injecting hundreds of people with cancer without their consent or knowledge.
When confronted about the ethical dubiousness of his procedures, Southam basically said that people were too ignorant to understand the importance of the study and that they would balk when they heard the word "cancer."
Oh, okay, then.
In other words, he knew they'd refuse his offer to be injected once they heard the "c" word.
Southam finally hit a brick wall when three Jewish doctors, well aware of the atrocious experiments conducted by the Nazis, refused to carry out his injection experiments.
Skloot explains the history of these Nazi experimentations and the results after the war.