Ugandan actress Nikita Pearl Waligwa, who was in the 2016 Disney film Queen of Katwe, has died at 15 years old.

Waligwa had been diagnosed with a brain tumor, BBC reports. After she initially found out she had a brain tumor in 2016, Queen of Katwe director Mira Nair reportedly urged people to donate to Waligwa's treatment in India. At the time, Ugandan doctors had said they didn’t have the necessary equipment to perform the operation.

They successfully removed the tumor and she was deemed healthy in 2017; however, they found another tumor last year.

Queen of Katwe is based on the true story of Phiona Mutesi, a chess prodigy from a Ugandan slum who began playing when she was nine. Even though she wasn’t in school, she learned the game and proceeded to compete in international tournaments.

Waligwa starred as Gloria, Phiona’s friend who helped her understand the rules of chess. Lupita Nyong’o played the role of Phiona’s mother, and David Oyelowo starred as her chess teacher.

In more heartwarming news, in January, Diddy used a viral video to inspire people to contribute to kids battling cancer. The children at the Miami-based nonprofit Fighting All Monsters put together a viral video where they danced to Diddy’s hit song “Bad Boys For Life.” Snoop Dogg was also featured. After Diddy shared the video, 100 iPads were donated, Apple asked how to be involved with the nonprofit, and hundreds of people asked how they could volunteer their time.