Martin Scorsese’s Oscar-nominated epic “The Irishman” probably wouldn’t exist if star Robert De Niro hadn’t read “I Heard You Paint Houses,” the book from which it was adapted, more than a decade ago.

The 2004 nonfiction novel by Charles Brandt chronicles the life of Frank Sheeran, a mafia hitman who confessed to killing union leader Jimmy Hoffa. De Niro says he first heard about the book from working with screenwriter Eric Roth, who wrote his 2006 film “The Good Shepard,” and then he later recommended it to Scorsese.

“Marty and I were working on a project before that, and it was a different type of genre film…I said, ‘Well, I have to read this book that I spoke with Eric Roth about a couple of years earlier when it came out,'” he explained during the Variety Screening Series. “There might be a lot of good research material here. I read it, and I said to Marty, ‘You’ve got to read this book. You’ll see.’ And that’s how it started.”

De Niro went on to play Sheeran in several different time periods in the film, thanks to de-aging special effects. He starred alongside Al Pacino and Joe Pesci, who both received Oscar nominations for supporting actor. “The Irishman” is also up for best picture and best adapted screenplay.

“It was all there in the book. It had so many great things in it. The way the Frank Sheeran character talks is totally believable, totally real. The situations he describes are real. You can’t fake that stuff. You know it’s coming from a real place. For Marty and our history of doing stuff, I thought this would be a really good thing to do,” De Niro said.