'Today' show host Savannah Guthrie's mother Nancy has gone missing. Here's what we know.

• Savannah Guthrie's mother, Nancy Guthrie, has been missing since Sunday.
• Authorities said they believe the 84-year-old was taken against her will.
• Savannah Guthrie has not appeared on "Today" since her mother's disappearance.

Nancy Guthrie, 84, the mother of beloved "Today" show host Savannah Guthrie, has been missing since Sunday, and authorities are investigating her disappearance as a crime.

Pima County Sheriff Chris Nanos said that based on the scene at her Tucson, Arizona, home, he believes this is a "possible kidnapping or abduction" case.

"Just call us. Let her go. Just call us. The family will tell you, there's no questions asked here," Nanos told NBC News.

Here's what to know.

Who is Nancy Guthrie?

Nancy Guthrie is the mother of "Today" show host Savannah Guthrie.

She has appeared on "Today" numerous times, including when Savannah called her on air in 2012 to wish her a happy 70th birthday. In 2022, for her 80th birthday, Savannah paid tribute to her mom on the show, calling her "a truth teller, whether you really want to hear the truth or not. She's quick and she's smart, she's well-read, she's curious about everything."

Last November, Nancy was featured in a segment where Savannah took a tour of her hometown of Tucson.

Nancy was last seen at her home outside of Tucson, Arizona, on the evening of January 31 after her family dropped her off there. She lives alone but has house staff.

The next day, Sunday, February 1, a friend called the family concerned when Nancy wasn't present for Sunday service at her church.

After an hour of searching the home and property, the family called 911. Authorities say her cell phone and car were left behind. She has limited mobility and requires daily medication that can be fatal if not received within 24 hours.

What do police think happened to her?

Authorities said they don't know if Nancy Guthrie was targeted because of her famous daughter and are not aware of any threats to Savannah Guthrie.

Along with investigating tips, authorities have been searching for Nancy using drones, a helicopter, an airplane, search-and-rescue dogs, and volunteers. Nanos said on February 3 that possible DNA evidence had been found at the scene, though it could take several days to learn anything conclusive.

ABC News reported that investigators are focusing on Nancy's electronic devices to see if there is data that could point to an assailant or a specific time when the abduction occurred.

What has Savannah Guthrie said?

Savannah Guthrie has been an anchor on NBC's morning show "Today" since 2012.

Born in Australia, she and her family moved to Tucson when she was young. She joined NBC in 2007, and in her time there before "Today," she was a White House correspondent and anchored "NBC Nightly News."

Savannah has not appeared on "Today" since her mother's disappearance.

On Tuesday, she posted an image on her Instagram that read "Please Pray" with the following caption:

we believe in prayer. we believe in voices raised in unison, in love, in hope. we believe in goodness. we believe in humanity. above all, we believe in Him.

thank you for lifting your prayers with ours for our beloved mom, our dearest Nancy, a woman of deep conviction, a good and faithful servant. raise your prayers with us and believe with us that she will be lifted by them in this very moment.

we need you.

"He will keep in perfect peace those whose hearts are steadfast, trusting in the Lord." a verse of Isaiah for all time for all of us.

Bring her home.

Guthrie is part of NBC's lineup to cover the upcoming Winter Olympics in Italy; it's so far unclear if she will still attend.