The Miracle Cancer Drug In 'The Fault In Our Stars' Doesn't Really Exist

If you get swept into the teen frenzy of "The Fault in Our Stars" this weekend, two things will happen.

The first is that it will reduce you to a puddle of tears.

Second, it will make you wonder if there's a miracle cancer treatment drug called Phalanxifor.

The adaptation of the best-selling young adult novel by John Green tells the story of two star-crossed lovers, Hazel (Shailene Woodley) and Augustus (Ansel Elgort), who meet at a cancer support group.

You soon learn that Hazel, diagnosed with thyroid cancer that spread to her lungs, is alive because of the experimental drug called Phalanxifor.

Fans of the book going into the movie know it's a fictional drug.

Green makes note of this in his acknowledgments at the end of the novel, saying he made the drug up simply because he would like it to exist. However, not everyone who sees the film is going to know that.

Business Insider headed to the inaugural Book Con (think of it as Comic Con for bookies) last weekend to see "The Fault in Our Stars" author himself speak on a panel for the film.

We caught up with Green on the phone the following day to discuss the book, its film adaptation, crying, and the fictional drug he put in the book.

He tells us that while Phalanxifor may not be real, it is inspired by very real cancer treatments.

"It's based on a couple of drugs that have emerged in the past decade or two that are extremely well-targeted drugs for very specific kinds of cancers like Herceptin, used for certain kinds of breast cancers," says Greene. "Then there's one that treats abdominal cancer."

"In both of those cases, people who are very, very sick and very close to death were able to maintain and recover their health and live, still with cancer, but with much longer lives," Greene added.

According to a pharmacist we spoke with, Herceptin is an IV drug used to treat patients with breast cancer who have the HER2+ gene.

If you're wondering why the drug is called Phalanxifor, look no further than the root word of the fictitious drug.

"I was imagining, the way that those drugs usually work, they connect to something in the molecule and the phalanx means like finger," says Greene. "I was imagining a drug that sort of connects like a key into a keyhole."