Linda Yaccarino, X CEO has announced that she is stepping down after two bumpy years running X.

X is Elon Musk’s social media platform.

Yaccarino posted a positive message Wednesday about her tenure at the company formerly known as Twitter and said “the best is yet to come as X enters a new chapter with” Musk’s artificial intelligence company xAI, maker of the chatbot Grok. She did not say why she is leaving.

Musk responded to Yaccarino’s announcement with his own 5-word statement on X: “Thank you for your contributions.”

“The only thing that’s surprising about Linda Yaccarino’s resignation is that it didn’t come sooner,” said Forrester research director Mike Proulx. “It was clear from the start that she was being set up to fail by a limited scope as the company’s chief executive.”