Syria's army is moving into northern Syria to repel a Turkish incursion now that U.S. troops are withdrawing. Fiona Hill, the Trump administration's former top aide on Russia, testifies on Ukraine.

Who is Marie Yovanovitch? The career diplomat's testimony today could play a significant role in the Trump impeachment inquiry.

Turkey pushes on in its assault of Kurdish forces in northern Syria as it faces international criticism. The latest NPR/PBS Newshour/Marist poll shows a slim majority of Americans favor House Democrats' impeachment inquiry into President Trump. And is China exporting censorship? Chinese pressure has pushed U.S. businesses to change the products they offer.

The U.S. has taken custody of high-value ISIS fighters as Turkey begins its offensive on the allied Kurdish forces that detained them. U.S. and Chinese negotiators return to the bargaining table in Washington. And we follow one of the first patients to be treated for a genetic disease using the gene-editing technique known as CRISPR.

In a letter, the White House declares Democrats' impeachment inquiry "constitutionally invalid" and refuses to cooperate in the probe. As the U.S. steps aside in northern Syria and Turkey steps in, how could ISIS benefit? A 17-year-old is the youngest to die from vaping-related causes. The rising death toll has led some states to ban certain products and put the spotlight on illegal vaping operations.

Ambassador to the European Union Gordon Sondland will testify on Capitol Hill on President Trump's dealings with Ukraine. Pentagon officials tell NPR that military leaders were caught off-guard by the White House announcement on Syria. And while China says it has released most Uighur and Kazakh Muslims from detention camps, detainees' families say many of them have been sent to prisons instead.