"Crazy, Stupid, Love." World Premiere - Arrivals

Julianne Moore and Marisa Tomei at the world premiere of Crazy, Stupid, Love in New York City, July 2011.

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Eight years after they costarred in Crazy, Stupid, Love—and nearly four decades after they attended Boston University together—Julianne Moore and Marisa Tomei have learned that they have much more in common than they thought. The surprise came courtesy of Tomei's appearance on PBS's genealogy show Finding Your Roots; upon turning the page of her so-called "book of life," which contains a group of genealogists' research conducted on her lineage, to discover her "genetic cousin," Tomei stared in shock at Moore's photo, then yelled out "Julianne?! Julie?!"

Naturally, it wasn't long before Tomei shared the news of the "incredible gift" she'd received from Henry Louis Gates Jr. on Instagram, posting a video of her discovery and couple of photos of her with her newfound older cousin on Tuesday. Clearly, Tomei, who's 54, and Moore, who's 58, were already close: "Eternally grateful for this generation and generations to come.... and the big surprise — discovering my friend is my REAL cousin! Hey cuz @juliannemoore!!!!," her caption concluded.

Moore also made that clear on her own Instagram by posting the same video, even an hour before Tomei herself. "I KNEW WE WERE ALIKE! @marisatomei is my COUSIN!! OMG I’m so excited," she wrote in the caption, which she polished off with the hashtag "#twinning."

The "most entertaining part" of the discovery, according to People, is just how unlikely it is that they share "an identical stretch of DNA" on Tomei’s X chromosome: Whereas all of Tomei's relatives that the show's genealogists were able to discover have roots in Italy, Moore mysteriously lacks any Italian heritage.

Still, this definitely isn't the first time that Finding Your Roots has made a surprising discovery, starting off with its first season in 2012, which saw Kevin Bacon and Kyra Sedgwick, who have been married since 1988, learn that they share distant ancestry. Similarly, last season saw Bernie Sanders and Larry David, who had in fact played the former on Saturday Live Night, learn that they're also distant cousins.

Not even Tomei and Moore's much more direct connection, however, has been able to top the show's most surprising discovery, which came in 2014 with the cameo of one Ben Affleck, who was nowhere near as thrilled about the discovery Gates made about his heritage—to the point that he persuaded the host not to share that some of his relatives were slave owners, which he later said "embarrassed" him.

There's a reason why you may be struggling to remember that episode: It caused such a stir that PBS not only withdrew it from all forms of distribution—save for three clips that remain available on PBS America’s YouTube channel—but also postponed the show's following season, citing concerns over "improper influence" and "censorship." (The revelation came via the infamous Sony email hacks in 2015.)

Hopefully, things will continue on a more positive note. Stay tuned to see whether the season's remaining guests—including everyone from Paul Ryan to Marina Abramović—will make any discoveries that will leave them as excited as Tomei.

Related: Julianne Moore's 14-Year-Old Daughter Liv is a Reluctant Celebrity Scion