In 2003, Carletta Tilousi, a member of northern Arizona’s tiny Havasupai Tribe, listened to a student’s doctoral presentation. She was there to hear the results of a diabetes study conducted, in part, with her DNA.

Or so she thought. As the student spoke, Tilousi realized that her DNA—and that of other members of the Havasupai Tribe—had been used for other studies, too. Some of the findings, it turned out, challenged her tribe’s traditional stories by suggesting the Havasupai people did not originate in Arizona. That genetic analysis, tribe members worried, could potentially pose a threat to their claims to their traditional lands.

Tilousi’s case is part of the reason that the Navajo Nation, the second-largest federally recognized tribe in the United States, continues to ban research using its people’s DNA. Since 2002, Navajo leaders and community members have opted out of genetic research because of suspicions about how their DNA would be used and a long history of distrust of the medical community’s motivations and methods.

In August 2017, a group of Navajo Nation leaders and community members came together to decide whether to lift the moratorium. “Navajo leaders, researchers, tribal members and even medicine men are pretty much in consensus,” reports Pauly Denetclaw for the Navajo Times. It’s now likely that the Navajo Nation will lift the ban.

The specifics of the new policy are still being hashed out. But one thing is already clear: This time, the Navajo Nation will be in control of their own people’s DNA.

That’s a dramatic break from the past—one in which Native American people’s bodies and genetic material have been violated and used without consent.

Native Americans’ bodies have been subjects of curiosity and medical experimentation since Europeans began to colonize North America. In the 19th century, academics applied pseudoscience like phrenology, which claimed that skull shape reflected intellect and morality, to Native Americans. According to historian Marren Sanders, phrenologists used the skulls of Native Americans to “prove” that “the Indians were ‘more ignorant and vindictive, blood-thirsty and cruel in war,’ and would ultimately ‘prefer extermination to slavery.’”

Phrenologists weren’t the only people interested in Native American bodies. Anthropologists and museum curators were too. Over the course of the 19th century, they collected Native American remains, even digging up graves, out of a desire to compare them to those of other races.

Often, these practices were used to justify the mistreatment of Native Americans, fueling mistrust in any scientific use of people’s bodies. And experiences like those of Tilousi made it even more difficult to trust researchers.

Though Tilousi and other Havasupai Tribe members thought they were donating DNA to a research project on type 2 diabetes, the material was also used for studies on things like schizophrenia, inbreeding and the tribe’s geographical roots.

To Tilousi and other tribe members, that felt like a violation. Though each of those topics is relevant to the scientific community, they are taboo within Havasupai culture. Genetic evidence that the Havasupai people migrated from the Bering Strait directly conflicts with the tribe’s understanding of its origins. Those stories hold that the Havasupai has always lived in Arizona, and that belief underlies the tribe’s claims on its traditional lands.

Some questioned the need to do scientific research about the genetic origins of Native Americans at all. As Kim Tallbear, an expert in racial politics in science and member of the Sisseton Wahpeton Oyate Tribe askedThe Atlantic’s Rose Eveleth, “We know who we are as a people, as an indigenous people, why would we be so interested in where scientists think our genetic ancestors came from?”

Though the researcher who used the Havasupai Tribe’s DNA for other purposes maintained she had received informed consent, the Havasupai Tribe sued. Eventually, it received a $700,000 payout. The case was compared to that of Henrietta Lacks, an African-American woman whose cells became the basis of thousands of medical studies and breakthroughs without her or her family’s knowledge or consent and without compensation.

Tribal sovereignty and a history of misused remains aren’t the only reason to question genetic research using the DNA of Native American people. To many Native Americans, there are serious ramifications for using a person’s biological material—whether they’re alive or dead.

“To us,” explained Frank Dukepoo, a Hopi geneticist, told the San Francisco Chronicle, “any part of ourselves is sacred. Scientists say it’s just DNA. For an Indian, it is not just DNA, it’s part of a person, it is sacred, with deep religious significance. It is part of the essence of a person.”

Now, reports Sara Reardon for Nature, the Navajo Nation will likely lift the ban and put a policy in place that dictates how testing is done, who oversees the genetic material and information about the DNA, and what’s done with the material once it’s been used.

That’s big news for scientists. The ban’s end means they’ll have the chance to work with genetic material donated by people from the Navajo Nation—material that could yield new scientific insights, fuel discoveries and potentially improve the health of Navajo people themselves with the development of specialized treatments based on genetic information.

Will the lift of the Navajo ban increase Native American participation in genetic studies? It’s hard to tell. But even if the use of Native Americans’ DNA becomes more common, misgivings will likely linger.

“As Native Americans, we have a problem with trust because we have been violated so much,” David Begay, a pharmaceutical scientist at the University of New Mexico in Albuquerque and a member of the Navajo Nation’s human-research review board, told Reardon.

Those violations may end in the future, but new policies won’t undo the pain of the past—or make it easier to move forward without justified suspicion.