The movie business is said to be one of those places where everyone knows everyone, and each big star can be connected to another by six degrees of separation - or usually less.
But Oscar-winning actress Marisa Tomei was surprised to learn just how close she is to another Hollywood actress. As it turns out, she's a blood relative to another major star.
The surprise came while Tomei was taping the PBS series Finding Your Roots, where celebrities dig into their past with the help of genealogists and DNA tests.
Instead of a historical figure or unusual ancestor, research into Tomei's past turned up actress Julianne Moore, who is actually Tomei's distant cousin.
"Julianne?" a shocked Tomei says on camera. "Julianne? Julie? You know we went to school together?"
Yes, it turned out that Tomei has another connection to Moore besides, as they both attended Boston University at the same time. The pair also co-starred in the movie Crazy, Stupid Love.
"Oh, I can't wait to tell her!" an excited Tomei said.
Researchers revealed that Tomei was related by "an identical stretch of DNA" to her "longtime friend" Moore. But they were just as surprised by the news as Tomei - since her ancestry is all Italian but Moore has no Italian ancestors that they know of.
Tomei shared a clip of herself learning the good news on Instagram, calling the surprise "an incredible gift."
"I KNEW WE WERE ALIKE!" Moore said on her own Instagram page. "[Marisa Tomei] is my COUSIN!! OMG I'm so excited," she added.
This isn't the first time Finding Your Roots has turned up a surprising celebrity connection. When they profiled Vermont Senator Bernie Sanders, they revealed he was a distant cousin of actor and comedian Larry David.
The relationship was ironic, since David played Sanders in skits on Saturday Night Live.
"People say to me, they talk about Larry David, and I say, 'He does a better Bernie Sanders than I do,'" Sanders joked.