Brady Kahle is only 10 years old and he’s already making the world a better place. After two of his friends were diagnosed with cancer, Kahle committed to selling his beloved baseball cards to help raise money for their treatment.

Get ready for a good cry.

“Proud seems like such a small word for what we feel,” Brady’s mom Jessie Kahle told ABC News. “How selfless he’s been has been pretty incredible. The way he’s so proud of what he’s doing. He’s always coming up with new ways to make it better and make it bigger. He’s so excited to make a difference.”

So far Kahle has raised $13,000 worth of cards for his friends Landen Palatino and Ben Manzi.

Manzi, 7, was diagnosed with leukemia in December 2015, while Palatino, 9, was diagnosed Jan. 8, 2016 with glioblastoma — a grade 4 brain tumor.

Brady has sold hundreds of thousands of baseball cards from the collection he started at 3 years old after setting up a table at The Boys & Girls Club of Chicopee, a youth development agency. His project is called “Cards for a Cause.”

Aside from his baseball cards, Kahle also sells bobble heads, signed hockey sticks, autographed baseballs, photos and original “Cards for a Cause” T-shirts, along with donated sports memorabilia.

“Most children Brady’s age would never want to give up cherished items and the fact that Brady wanted to sell his beloved cards to help us, is beyond heartwarming,” Tina Palatino, the mother of 9-year-old Landen Palatino, told ABC News. “Landen has always looked up to Brady and I think this just makes him look up to him even more.”