Tribe spokeswoman Julie Hubbard told The Associated Press on Friday that Warren had apologized "for causing confusion on tribal sovereignty and tribal citizenship and the harm that has resulted."
Warren released her DNA test results in October as evidence she had Native American heritage in her bloodline in October, with many Native Americans deriding the official for mistaking DNA with identity.
Though Warren's test revealed that she may have Cherokee blood, and though she was told her great-great-great-grandmother was Cherokee, "that doesn't mean the woman was pure Cherokee," Politifact reported.
"Different families and groups interacted in different ways with European settlers in the region," Deborah Bolnick, University of Connecticut professor and past president of the American Association of Anthropological Genetics, told Politifact. "When there was intermarriage, the offspring sometimes became part of indigenous communities, and sometimes they identified with nonindigenous groups."
There aren’t any genetic markers specific to tribal nations, she added. “The genetic patterns don’t map onto tribal groups that we recognize today.”
The Cherokee Nation complained then that tribal nations, not DNA tests, determine citizenship and that Warren was “undermining tribal interests with her continued claims of tribal heritage.”
Warren's campaign declined to comment to The Associated Press.
The Associated Press contributed to this report.