Facebook is losing the two cofounders of one of its most prized acquisitions.

Instagram cofounders Kevin Systrom and Mike Krieger told Facebook executives on Monday that they plan to leave Facebook in the coming weeks, the New York Times first reported. Systrom is currently Instagram’s CEO, while Krieger is the CTO.

Systrom confirmed the news in a statement shortly after the New York Times’ story was published. He wrote:

Mike and I are grateful for the last eight years at Instagram and six years with the Facebook team. We’ve grown from 13 people to over a thousand with offices around the world, all while building products used and loved by a community of over one billion. We’re now ready for our next chapter.

We’re planning on taking some time off to explore our curiosity and creativity again. Building new things requires that we step back, understand what inspires us and match that with what the world needs; that’s what we plan to do.

We remain excited for the future of Instagram and Facebook in the coming years as we transition from leaders to two users in a billion. We look forward to watching what these innovative and extraordinary companies do next.

Facebook acquired Instagram in 2012 for $1 billion, a deal that was criticized at the time but that looks like a bargain now that the app has more than 1 billion monthly users.

Instagram has proven to be a pivotal asset for Facebook as users have grown skeptical of its main app in the wake of the Cambridge Analytica scandal earlier this year. In the first quarter of this year, Facebook reported a decline in North American users, while Instagram usage on the continent continues to grow. Stories — the ephemeral video format the company believes to be the future of content-sharing on social — is seeing more traction on Instagram, which adopted the format first, than on Facebook.

And Instagram is where the company is experimenting with the launch of a shopping vertical and its long-form video hub IGTV — the success of which could determine how Facebook is able to integrate those features and potentially valuable new revenue streams into its main app.

Systrom and Krieger mark the second high-profile departure this year of cofounders of a company Facebook has acquired. In April, WhatsApp cofounder and then-Facebook board member Jan Koum announced he was leaving the company. His cofounder, Brian Acton, left Facebook last September.

Update at 8:05 p.m. Pacific: Updated with comment from Systrom, confirming that he and Krieger are leaving Facebook.