By Alex Heigl
UPDATED 02/27/2014 at 03:15 PM EST
The next time you think about the power of friendship, think about Dylan Siegel.

Dylan is 7 years old. His best friend, Jonah, has an extremely rare liver disease, and funding for his treatment almost dried up at one point. So Dylan decided to help by writing a book, The Chocolate Bar Book, which has helped raise over $600,000 for research into Jonahs disease.

Jonah has Glycogen Storage Disease Type 1b, which is a rare liver disorder that causes dangerously low blood sugar. As one of 500 children in the world with the disease, Jonah has to be fed every few hours through a feeding tube in his stomach. There is currently no cure.

Dylan describes his friendship with Jonah as awesome as a chocolate bar, which is where he got the title of his book. People in all 50 states and 42 countries have purchased copies of The Chocolate Bar Book, with every cent going to Dr. David Weinsteins Florida lab, where a cure for the disease is apparently near to being reached.

It is now reality. Its not just a dream that these children can be cured, Dr. Weinstein told ABC affiliate KGO-TV.

Dylan seems to think so, anyway. Asked where he and Jonah would be 10-15 years from now, he told KGO-TV, Um, high school and probably [Jonahs] disease would be cured.

Jonahs answer to the same question?

Friends.