Sam Altman is planning to step down from his role as president of Y Combinator, one of the best-known startup accelerators in Silicon Valley. He’s leaving the position to focus on his work as cochair of prominent nonprofit research organization OpenAI, Y Combinator announced today.

OpenAI was created in 2015 with $1 billion in funding from YC Research and people like Altman, SpaceX cofounder Elon Musk, investor Peter Thiel, LinkedIn cofounder Reid Hoffman, and Y Combinator founding partner Jessica Livingston.

OpenAI has tackled a number of AI research initiatives. In recent weeks, the nonprofit launched a massive reinforcement learning simulator and controversial state-of-the-art NLP model GPT-2 and advocated that sound AI systems rely on social science as well as computer science.

Altman, the organization’s second president since the accelerator was created, will continue at Y Combinator as company chair. Other YC partners will pick up additional day-to-day operations as a result.

Y Combinator is also considering a move from Silicon Valley to San Francisco, according to a blog post.

“The center of gravity for new startups has clearly shifted over the past five years, and although we love our space in Mountain View, we are rethinking whether the logistical tradeoff is worth it, especially given how difficult the commute has become,” the blog post reads. “We also want to be closer to our Bay Area alumni, who disproportionately live and work in San Francisco.”

Y Combinator is currently recruiting its 29th class of startup companies. More than 2,000 startups from around the world have participated in the Y Combinator startup accelerator since it was founded in 2005. Each graduate receives $150,000 in backing and three months of training and prep to scale their business.

Last year, Y Combinator announced plans to open a YC Research facility in Seattle and expanded into China, with former Baidu and Microsoft executive Qi Lu leading efforts in both new initiatives.