Transgender teen Gavin Grimm has received the backing of dozens of corporations -- including heavyweights like Amazon, Apple, Microsoft and Twitter -- have signed on to a "friend of the court" brief backing Grimm in his case against his school district over bathroom choice.

The brief, put together by the Human Rights Campaign, features 53 corporations in all and should be filed on Thursday in support of Grimm's case, G.G. v. Gloucester County School Board.

Besides the aforementioned corporations, the brief boasts several other big tech companies, including Airbnb, Box, Lyft, Tumblr, and Yahoo. The brief also includes the support of non-tech corporations like Gap, MAC Cosmetics, and Warby Parker.

In their statement posted online, Tumblr said, "[Trans youth] deserve, as do all students and all people, to be protected equally by the institutions designed for them."

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Many of the tech corporations who signed this brief also publicly slammed President Donald Trump when, last week, the administration eliminated protections for transgender students that allowed them to use public school bathrooms that matched their gender identity. 

Noticeably absent from the list, as noted by Gizmodo: Uber (who intended to join the group but missed the deadline), Google, and Facebook.

Chad Griffin, president of the HRC, said in a statement, “Across the country, corporate leaders are speaking out because they know attacking transgender youth isn't just shameful -- it also puts the families of their employees and customers at risk. Transgender students like Gavin are entitled to the full protection of the law, and must be affirmed, respected and protected in the classroom and beyond.”

According to the ACLU, which has taken up Grimm's case, Grimm is forced to use a "converted utility closet or another, separate, stigmatized space every time he needs to use the restroom during the day," because he is barred by the school board from using the same facilities as his peers.

When Grimm's parents informed the school of his gender in the 10th grade, the principal and the school initially treated him as a boy for all purposes — including use of the restroom.

But then residents of Gloucester County complained, putting pressure on the board to pass a policy to bar kids with "gender identity issues" from using the bathroom. It passed, and Grimm was prohibited from using the boy's restrooms.

While the Grimm's fight has lingered for two years, it gained new attention when Laverne Cox, presenting at the Grammys, gave her support to Grimm and called on others to follow his case.

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Oral arguments are scheduled at the Supreme Court later this month, the first time the nation's high court will hear a case on transgender rights.

Read the entire brief below.

UPDATE (1:30 PM ET): Updated to include statement from Tumblr and other details

Additional reporting by Johnny Lieu and Colin Daileda