Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, has been one of the most visible health officials in the federal government's response to the coronavirus outbreak.

Normally stoic and even-keeled, Fauci briefly broke his poker face during Friday's press briefing.

When President Donald Trump went on a tangent and joked about the State Department — calling it "the Deep State Department," alluding to an unsubstantiated conspiracy against him by civil servants — Fauci covered his face.

The moment did not go unnoticed on social media — clips were shared on Twitter almost immediately afterward.

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Dr. Anthony Fauci has been a stoic and even-keeled public-facing official in the federal government's response to the coronavirus outbreak, but one quip from President Donald Trump during a Friday press conference broke his poker face.

Fauci, 79, the director of the National Institute of Allergy and Infectious Diseases since 1984, has become a household name since COVID-19 — the illness caused by the coronavirus — began dominating the news cycle as it spread worldwide.

The infectious-disease expert took questions at a few points during the briefing and remained steadfast by Trump's side. Except when the president went on a tangent about the State Department.

When Trump referred to it as "the Deep State Department," Fauci glanced to his right and appeared to chuckle to himself before covering his face with his palm.

Shortly afterward, Twitter lit up with users weighing in on the "Fauci facepalm."

Many shared the image or video with some variation of "Dr. Fauci is all of us right now" as the moment became a meme.

Others mocked Fauci for touching his face, going against some of the Centers for Disease Control and Prevention's earliest guidance about the virus.

Some seemed to think Fauci was in on Trump's joke with Secretary of State Mike Pompeo, who faced questions from reporters during the press conference about his penchant for lashing out at journalists.

Earlier in the press conference, Fauci was undercut by Trump on whether an unapproved treatment for COVID-19 was safe.

The doctor has been a staple of televised federal responses to the outbreak and has found himself having to toe the line between conveying accurate information and not undermining the president, whose message has often differed from that of public-health experts.