The U.S. Supreme Court on Tuesday let stand a lower court's ruling favoring transgender students.

The case involves the Boyertown Area School District, which in 2016 began allowing transgender students to use the restrooms and locker rooms of their choice.

Last year, the Third Circuit Court of Appeals upheld the Pennsylvania school district's policy.

The Alliance Defending Freedom (ADF), a Christian conservative group representing an anonymous group of students and parents, appealed the decision to the Supreme Court.

The high court announced on Tuesday that it would not hear the case of Doe v. Boyertown.

In its 32-page petition to the Supreme Court, ADF asserted that the Boyertown Area School District's policy violates the right to privacy of the students it's representing.

“Forcing a teenager to share a locker room or restroom with a member of the opposite sex can cause embarrassment and distress, particularly for students who have been victims of sexual assault,” the petition reads.

The American Civil Liberties Union (ACLU) intervened in the case on behalf of the Pennsylvania Youth Congress, a coalition of LGBT youth organizations.

“This is an enormous victory for transgender students across the country,” ACLU attorney Ria Tabacco Mar said in a statement. “Boyertown’s schools chose to be inclusive and welcoming of transgender students in 2016, a decision the courts have affirmed again and again. This lawsuit sought to reverse that hard-won progress by excluding transgender students from school facilities that other students use. That would have increased the stigma and discrimination that transgender students already face.”

“Thankfully, today’s announcement allows schools to move forward with policies that support transgender students. But our work is far from over. We will continue to defend the transgender community from attacks in the courts, the legislatures, and the White House.”

Aidan DeStefano, a transgender student who recently graduated from Boyertown High, added: “By the time I graduated high school, I was using the boys’ bathroom and participating on the boys’ cross country team. I felt like I belonged and had the confidence I needed to continue with my education. I’m glad the Supreme Court is allowing schools like mine to continue supporting transgender students.”