Mack Beggs, 17, is an undefeated wrestler high school wrestler who is nearly two years into a female-to-male transition. He's competing in this weekend's Texas state championship -- in the girls division.
During his transition, Beggs has been taking testosterone.
But because he's listed as female on his birth certificate, the statewide University Interscholastic League won't let Mack wrestle boys. So, the Trinity High School junior been wrestling -- and winning -- against girls all season.
Earlier this month, the parent of a competitor of Beggs filed a lawsuit demanding the league place Mack in the boys' division, despite his birth certificate.
“There’s a reason they’re called performance-enhancing drugs and why they’re banned by every anti-doping agency in the world,” said the father who filed the suit, according to the Fort Worth Star-Telegram. “There’s no question it is an advantage.”
The league granted Beggs permission to take testosterone because he is using the hormone for a "valid medical purpose," the newspaper reported.
Beggs is 54-0 this season as of Friday, when he won his first and second match in the state tournament, the Dallas Morning News reported.
Beggs advanced to the semifinals after winning his second match, when he was met with a few boos, according to the News.
"Mack wants to wrestle boys and he'll never be recognized as a boy because of the birth certificate in the state of Texas," a woman whose daughter lost to the teen told the newspaper. "Female wrestlers don't have a chance."
During Friday's matches, reporters and news cameras surrounded Beggs. He didn't acknowledge their presence, going to the weigh-in like any other wrestler, the News reported.
The News reported that Texas school district superintendents last year voted overwhelmingly to approve a policy requiring that students compete against the gender that matches their birth certificate.
Mack's story is in the spotlight the same week as President Donald Trump rolled back Obama-era guidance for transgender students' bathroom use at schools.
In May 2016, the U.S. Justice and Education departments issued joint guidance telling schools to let transgender students use facilities corresponding to their gender identity. The Trump administration's letter to educators on Wednesday offered no substitute guidance but simply withdrew the Obama directive.