In a note on Thursday morning to YouTube employees, Susan Wojcicki announced her departure.

“Today, after nearly 25 years here, I’ve decided to step back from my role as the head of YouTube and start a new chapter focused on my family, health, and personal projects I’m passionate about,” she wrote.

Wojcicki went on to say that she was empowered to make the decision because of the “incredible leadership team in place” at the company. Wojcicki will be replaced by Neal Mohan, who has been the YouTube’s chief product officer since 2015, and joined in 2007.

“He has a wonderful sense for our product, our business, our creator and user communities, and our employees. Neal will be a terrific leader for YouTube,” Wojcicki wrote. She added that she will help him with the transition, and she will be taking on an “advisory role” across Google and Alphabet, which owns YouTube.

Wojcicki joined Google in 1999, and worked as the SVP of Adwords and AdSense before taking on her role as YouTube CEO. At YouTube, Wojcicki launched YouTube’s partners program to take advantage of the blossoming creator economy. Ad revenue for the service hit $28.8 billion In 2021. She was ranked as number 20 on Fortune’s list of the 50 Most Powerful Women in 2022. If it were a standalone company, YouTube would rank at number 121 on the Fortune 500.

During Wojcicki’s tenure, YouTube has struggled with battling misinformation in videos posted by its users on topics like COVID, politics, and Russia’s invasion of Ukraine.

She has been among the most prominent female leaders in a tech industry that is overwhelming dominated by men, and is only one of 45 female leaders of Fortune 500 companies. In 2022 she gave an interview to Fortune Editor-in-Chief Alyson Shontell in which she weighed in on the leaked Supreme Court memo about overturning Roe—something that did eventually come to pass.

“My stance is that women should have a choice when they become a mother, I believe that’s really important,” she said. “I believe reproductive rights are human rights, and to take away a law and a right that we’ve had for almost 50 years will be a big setback for women.”

Wojcicki took the opportunity in her resignation letter to thank Google and Alphabet CEO Sundar Pichai for his support. But she opened by talking about Google co-founders Larry Page and Sergey Brin, who she met 25 years ago, and her choice to join their budding search engine that has since become one of the most world’s most successful companies.

“It would be one of the best decisions of my life,” she wrote.

This is a breaking story please check back for updates