'The Fault In Our Stars' Most Emotional Song Was From Director's Own Cancer Experience

M83's 'Wait' was a request based on director Josh Boone's time with a dying friend.

When director Josh Boone set out to make "The Fault In Our Stars" he knew there was one song that absolutely had to be in the movie.

"I pitched it to Fox as not a cancer movie," Boone told MTV News about the adaptation of the John Green young adult novel, which hits theaters June 6. The story follows teen cancer patients Hazel (Shailene Woodley) and Gus (Ansel Elgort) as they fall in love and fight illness in one fell swoop.

"I said this is 'Titanic' and cancer is the iceberg," Boone added. "The iceberg is not as important as the love story that's on the boat."

Boone has confronted that iceberg in his own life, and felt strongly that the song that had soundtracked the time he spent with a friend fighting cancer, M83's "Wait," should also be in the movie.

"I had a really close friend die of Stage 4 lung cancer and I was in hospice with him and in the hospital, and with him at home when he was back home and sick," Boone said. "When I was in the hospital with him that M83 album had just come out and I listened to one song over and over."

The song, which originally appeared on the album "Hurry Up, We're Dreaming," features a repeating chorus of the line "no time, no time." It plays twice in the movie, including once toward the end when audience waterworks will surely be flowing.

There was also an element of serendipity that led to the song's inclusion in the film: Season Kent, the music supervisor for "Fault," made a mix tape of songs she felt represented the mood of the movie before filming was underway. When she shared the tape with Boone, to see if their musical tastes, as she said, "vibed," "Wait" was on the tape. She had not met Boone or heard the story when she made the tape.

"That song has a lot of special meaning to him," Kent said. "For me, it's just one of those nugget songs, is what I call it. It's one of those songs that I love that needs a big film placement and has such special meaning."

"It's really perfect for our film," Kent continued. "It was so exciting that we both had this song that we didn't even talk about, and he knew he wanted the song in the movie, and we made it happen."

"The Fault In Our Stars" hits theaters June 6.