Mika Brzezinski has risen to defend NBC News chairman Andrew Lack, whom President Trump attacked in a tweetstorm this morning.

Trump, apparently reacting to a New York Post Page Six report that Lack was about to be dismissed, tweeted out that Lack “is about to fired (?) for incompentence, and much worse.”

Brzezinski responded on her MSNBC Morning Joe show. “Not only is he attacking NBC’s chairman Andy Lack, our boss, with stupid rumors, but also he’s going after the truth,” she said.

Trump also attacked CNN president Jeff Zucker, calling for his firing over a story sourced by Michael Cohen attorney Lanny Davis, who has since walked back his previous statements. CNN continues to stand on its story, despite the Davis clarifications.

Lack, a veteran newsman, has been chairman of NBC News and MSNBC since 2015.