When Alfonso Gomez-Rejon first read the script for “Me, Earl and the Dying Girl” he couldn’t help but feel like it was meant for him to direct.

“I had gone through a very personal loss in my life and felt very much like Greg,” Gomez-Rejon said. “So by making a movie out of it I was able to best express myself because it was hard to find a way, certainly with words, to deal with it.”

The film revolves around three teens, one just diagnosed with cancer. Greg (Thomas Mann) is forced by his mom to hang out with “the dying girl” Rachel (Olivia Cooke). With the help of his so called “co-worker” Earl (RJ Cyler), Greg helps Rachel travel through the ups and downs of her illness by keeping her spirits up using his and Earl’s bad remakes of classic films. Greg, who at the beginning of the film finds himself without any real friends or connections, ends up understanding and appreciating the beauty of friendship, regardless of the hassle it may bring.

But making the story of a young girl with cancer come to life needed the talent and commitment of the cast. Olivia Cooke was picked to play the role of Rachel, a teen well past her years battling Leukemia. The role was nothing like anything Cooke had done before, so preparing for it required intensive research and creating charts of how Rachel’s illness progressed and how it would be reflected in Cooke’s performance.

“I went to visit the Mattel wing at UCLA and met a girl named Katie and met the doctors that were treating her and she had the same Leukemia as Rachel in the film,” Cooke said. “Just seeing her, being so still on the bed, and she had One Direction posters on the walls … it really helped. I just wanted to make (the movie) as honest as possible … because if someone watching my performance or the movie had gone through that and kind of felt like it wasn’t an accurate representation then it would crush me.”

Alongside Cooke were Mann and Cyler, each with different levels of experience. But director Gomez-Rejon pushed the actors into allowing themselves to be vulnerable on screen from day one. For Cyler this was his first big-screen project.

“I’m not really emotional, like at all, in life in general. So I mean, Alfonso, he would show me little like ways and tidbits of just letting myself go there,” Cyler said. “(The cast) just made me comfortable to the point where I was like ‘I could cry for 16 hours with them’ you know because they just made me comfortable.”

Mann had to portray vulnerability from a different angle.

“Greg has a fear of being vulnerable and so it’s about him letting go of that and learning to share himself and let people in,” Mann said. “So really it was just kind of trusting that I was the right person for the job and that it was going to be okay.”

Trust played a major part in filming this film, especially for Cooke who two weeks before pre-production decided to shave her head for the film.

“We decided to shoot the shaving of the head as our characters because it was going to be maybe a part of the film … these guys were cutting little pig tails off, having the best time ever,” said Cooke. “I was just rubbing my scalp for the first time ever and I was trying not to cry because the whole point was taking control of the cancer before the cancer took control of Rachel, but I couldn’t help it and I let out this weird scream cry noise that has never been emitted from my body before.”

The actors and director agree that that scene raised the bar for the production.

“All of a sudden you see all of her hair on the ground and I look at Olivia and she’s like tearing up and you realize this is real, like yeah she’s playing a character but that is her real hair on the ground,” Mann said.

But despite the difficult topic, Gomez-Rejon believes the film is about much more than just cancer.

“It’s about living, it’s about discovery, and it’s about creating,” he said.

“Me, Earl and the Dying Girl” is in theatres June 12.