The Incredible True Story of Henrietta Lacks -- the Most Important Woman In Modern Medicine

Henrietta Lacks was just 30 years old when she discovered a lump on her cervix while in her bathtub at home.

A private-care doctor referred her to Johns Hopkins Hospital for further testing and she was diagnosed with cancer in January 1951. Lacks, the wife of a steelworker and a mother of five, was treated with radiation and sent home, but she was hospitalized the following August. She died at the age of 31 two months later.

But that’s not where her story ends.

Without her knowledge or permission, doctors harvested samples of Lacks’ cervical tissue during her treatments and discovered her cancerous cells were not like any other they’d seen - they were able to duplicate in labs and stay alive. This meant that the same sample of tissue could be tested multiple times for research, making her cell line immortal.

Research using Lacks’ cells helped spur numerous medical breakthroughs, include vaccines, cancer treatments and in vitro fertilization. But, for decades, her family was kept in the dark about her second life - and were never compensated for her contributions.

Henrietta Lacks

Now, Oprah Winfrey is executive-producing and starring in an HBO movie adaptation of The Immortal Life of Henrietta Lacks - the New York Times best seller by Rebecca Skloot that detailed how Lacks’ cells came to be known as the HeLa line, and how its existence has impacted the family she left behind.

“They did what they’d never had another human cell do - duplicate itself and then duplicate itself and then duplicate itself,” Winfrey, who plays Lacks’ daughter Deborah in the movie, tells PEOPLE during the latest edition of The Jess Cagle Interview, excerpted in this week’s issue. (You can watch a video clip of it above.) “That’s why it’s called the Immortal Life of Henrietta Lacks, because her cells even now as we speak are still replicating somewhere in some tube.”

HeLa cells have contributed to medical advancements like the polio vaccine and have been used in gene mapping and AIDS and cancer research. And although Lacks died in 1951, her family didn’t know that her cells were still alive in labs all over the country. That all changed in 1973, when doctors requested blood samples from them after HeLa inadvertently contaminated other samples.

“Her family didn’t know that anyone had taken her cells until much later on. Once they discovered it, trying to figure out how it all happened - and how it unraveled and multi-millions of dollars, now billions of dollars, have been made off of the cells - is the story of the Immortal Life of Henrietta Lacks,” Winfrey says during the interview, which took place at The London West Hollywood in Beverly Hills.

Byrne and Winfrey as Skloot and Deborah
  • Watch the full episode of The Jess Cagle Interview: Oprah Winfrey, streaming now on People/Entertainment Weekly Network (PEN). Go to PEOPLE.com/PEN, or download the app for Apple TV, Roku, Amazon Fire TV, Xumo, Chromecast, Xfinity, iOS and Android devices.

The movie, airing April 22, explores the family’s hardships after finding out about the existence of the cells - and their thwarted attempts to gather more information.

And though Skloot - played by Rose Byrne in the movie - originally set out to tell Lacks’ tale, the author quickly realized the story went far beyond the woman behind the HeLa cells when she talked to Lacks’ daughter Deborah for the first time in 1999.

“To me, it was not only about the woman, but what that does to a family,” Skloot tells PEOPLE. “Deborah and I were both driven by this same obsessive passion to just answer these questions: Who was she? What happened? What can be done to make it so it doesn’t happen again?’ “

RELATED: Rose Byrne on Working With Oprah in The Immortal Life of Henrietta Lacks’

Although Deborah and Skloot shared this common goal, it took years for the second-youngest Lacks child to trust her. The family had gone through years of alleged mistreatment from medical professionals and were burned by people who had tried taking advantage of their connection to the famous HeLa cells. Skloot had to overcome these insecurities and show Deborah she could be trusted with her mother’s story.

“For me, the process of winning her trust was about figuring out why she was afraid,” she says. “I knew something happened to her that made her scared of me. It was definitely like the way you see it in the movie where we would go forward and good things would happen and she would panic and push me away. Usually it was because something happened related to her traumatic experiences and she would get scared and really challenge me.”

Skloot and Deborah in 2000

Their contentious relationship continued as Deborah’s older brothers repeatedly tried to stop her from talking to Skloot, and tensions boiled over one day in a hotel room when Deborah, frightened and defensive, pushed Skloot against a wall. Still, the two continued to work together, eventually establishing a trust and friendship that led them to discover more about the mother Deborah never got to know.

Deborah died in 2009 before the book was published, but she did get to see her mother for the first time thanks to her work with the author. In 2001, Skloot, Deborah and her brother Zakariyya got the chance to visit Johns Hopkins and see the HeLa cells.

“It was one of the most incredible and powerful moments of my life,” Skloot says. “That was the closest thing they’d ever seen to their mother being alive since they have no memory of her. It was beautiful for them to be in the presence of her in a way that felt the closest to her being alive. She knew that that wasn’t her mother obviously, but it was like being able to have closure in a really beautiful way.”

This article was originally published on PEOPLE.com