Roland A. Pattillo, a gynecologic oncologist who had been treating and researching female cancers for decades, had long been haunted by the curious case of Henrietta Lacks, a young, impoverished Black woman who died of cervical cancer in 1951 yet whose cells lived on and made medical history.

They were known as the HeLa cell line, and they had been used to develop the polio vaccine, treatments for HIV, and other landmark medical advances. Like most medical researchers, Dr. Pattillo had known about the HeLa cells since he was a graduate student. As it happened, he had also been a fellow in the Johns Hopkins lab in Baltimore that had first cultured them, one of the few Black doctors working there in the late 1960s.

But unlike many other scientists, Dr. Pattillo was keenly focused on the fact that there was a human behind those cells and that she had left a family behind. For years he had wanted to honor her contributions to science.

In the early 1990s, when he arrived at the Morehouse School of Medicine in Atlanta, a historically Black institution, to help start its residency program and direct its gynecology oncology department, Dr. Pattillo organized a symposium on the HeLa cells and dedicated it to Henrietta Lacks.

The topic that first year — it is now an annual event — was disparities in the survival rates of Black and white cancer patients. He successfully petitioned the mayor of Atlanta to name the date of the first conference, Oct. 11, 1996, Henrietta Lacks Day. And he was determined to involve her family in the event.

Dr. Pattillo tracked down Henrietta’s daughter, Deborah, who was living in Baltimore, and invited her and her brothers to the conference. She was thrilled. She was barely 2 years old when her mother died and had grown up wondering about her, mystified by her medical legacy. Dr. Pattillo would not just honor Henrietta, Deborah understood; he would be the first scientist to explain what had happened to her mother.

Dr. Pattillo, who became an advocate for Henrietta Lacks’s family and played a pivotal role in Rebecca Skloot’s best-selling 2010 book, “The Immortal Life of Henrietta Lacks,’’ died May 3 at his home in Newnan, a suburb of Atlanta. His death, at 89, went largely unreported at the time, coming to light in late September in an article in The Nation magazine.

His wife, Patricia O’Flynn Pattillo, said the cause was Parkinson’s disease.

“Dr. Pattillo was the first person from the world of science to take a step back and say, ‘These cells came from a Black woman who had a family, and she needs recognition and they need peace,’’’ Skloot said in a phone interview. “He was also the first person from the world of science to treat Deborah like a human being. To see her as a young woman who was desperate to learn about her mother. He gave her a voice. He was a constant touchstone for her.’’

Henrietta Lacks was a 30-year-old mother of five when she walked into the gynecology clinic at Johns Hopkins Hospital in Baltimore, the rare public hospital in the Jim Crow era to treat Black patients. She was suffering from what turned out to be an extremely aggressive tumor on her cervix.

Some of the tumor’s tissue was taken to George Otto Gey, a cancer researcher at the hospital, where he had been trying, unsuccessfully, to grow human cells for years, collecting tissue from patients in the hope of doing so. Lacks was treated for her cancer, but it spread, and she died later that year, two months after turning 31.

Yet her cells did not die; cultured in Gey’s lab, they reproduced at a remarkable rate. It was Gey who named the cell line HeLa, and they would become known as “immortal’’ cells — they are still alive today — and profoundly alter modern medicine. HeLa cells were also sent into space, used in cosmetics testing, and employed in the development of the vaccine for HPV, the virus that caused Lacks’s cancer.

Gey gave HeLa cells away, but soon biotech companies sprung up to sell them. At one point it was estimated that if all the HeLa cells ever grown were placed on a scale, they would weigh more than 100 Empire State Buildings.

While scientists delighted in HeLa’s powers, Lacks’s family, particularly Deborah, were horrified and confused by the story of the HeLa cells. Deeply religious, they didn’t understand why Henrietta’s cells had been taken from her — and without her knowledge — and why they were still living. Nobody had bothered to explain any of this until Dr. Pattillo reached out to them.

It was standard practice to take tissue without consent when Henrietta was being treated (today consent is required for some but not all tissue research). The Lacks family knew enough about episodes of heinous treatment of Black patients historically to wonder if Lacks’s tissue had not been extracted for nefarious means. They knew about the notorious Tuskegee studies in Alabama, where Black men with syphilis were told that they were receiving medical care when in fact they were being studied for the effects of the disease; more than 100 men died from lack of treatment.

Dr. Pattillo was able to assuage Deborah’s fears that her mother had been denied proper care.

Dr. Pattillo was initially wary of Skloot’s intentions in writing about the Lacks family. He had resolved to protect Deborah from what he saw as the bunglings, reflexive racism, and ethical lapses of the white scientists and journalists who had long reached out to her. At one point in the 1970s, researchers took blood samples from the family without explaining why. The researchers were looking for a particular genetic marker. But the Lacks family thought they were being tested to see if they might develop Henrietta’s cancer. For years, Deborah lived in fear that she would die from it.

Dr. Pattillo would eventually guide Skloot in her work, to make sure she got the story right.

He advised Skloot when she created a foundation to support the education and health needs of the descendants of Henrietta Lacks and others who were used in research without their knowledge or consent, and he served on its board.

Deborah Lacks died of a heart attack in 2009, the year before Skloot’s book was published, but Dr. Pattillo stayed in touch with the family.

“He was a kind man that I could trust, that the family could trust,’’ Jeri Lacks Whye, one of Henrietta Lacks’s granddaughters, said by phone. “His compassion to our family has trickled down throughout generations.’’

“He was focused particularly on getting Black women access to care, and on making them feel heard and seen,’’ Skloot said. “That was the thread that ran through his whole life.’’

Roland Anthony Pattillo was born June 12, 1933, in DeQuincy, La. His mother, Rhena (Shaw) Pattillo, was a homemaker; his father, Anthony Pattillo, was a steelworker.

In addition to his wife, Dr. Pattillo leaves his children, Catherine, Mary, and Patrick Pattillo and Sheri Pattillo Johnson; his stepson, Todd Thomas, who is called Speech; a sister, Carolyn Pattillo Davis; and eight grandchildren. An earlier marriage, to Marva Parks, ended in divorce.

When Henrietta Lacks died, she was buried in the Lacks’s family gravesite in Clover, Va. But she had no gravestone or marker. In 2010, Dr. Pattillo and O’Flynn Pattillo raised the funds to buy her one, a pink granite slab carved in the shape of a book. The inscription reads, in part: “Here lies Henrietta Lacks (HeLa). Her immortal cells will continue to help mankind forever.’’