2-year-old Callen has always been a ball of energy. He’s obsessed with swimming (aka jumping into the pool face first) and is beyond excited to have a new baby sister.

A week before Callen’s second birthday in February, he was suddenly having trouble breathing. A string of ER visits and discharges followed… his parents were repeatedly told to take him home and monitor him.

Callen’s mom, Tori, was terrified that he’d go into respiratory failure. She sought another opinion from his pediatrician who suspected pneumonia and sent them back to the ER.

This time, blood tests were done. Tori thought he might have asthma, but when the doctors came back with sunken faces to share the results, she knew it was much worse. All signs pointed to blood cancer.

Callen was rushed to the Children’s Hospital of Philadelphia where his family was given the heartbreaking diagnosis… he had acute myeloid leukemia (AML).

The disease had already caused one of his lungs to fill hallway with fluid.

Their normally high-energy little boy was swollen and lethargic. Callen was immediately hooked up to a chest tube to drain the fluid from his lungs, his mom telling us, “He had more wires on him than I’ve ever seen on anyone.”

Callen celebrated his second birthday in hospital, birthday cake and all, and then started a 4-round chemotherapy regimen. Thankfully, he has been in remission since his very first round of treatment.

According to his mom, Callen has taken everything like an absolute champ. When he’s done with a chemotherapy session and the nurses unhook the IV line, he’ll run around the room yelling, “I’m a free man!”

And he has consoled her in those moments when it all gets too much. He’ll put a hand on her back and tell her, “It’s okay mommy, it’s not scary,” and wipe her tears.

Callen’s type of AML comes from an extremely rare genetic mutation with very little research behind it. Doctors don’t know how much the mutation heightens the possibility of recurrence.

His story is a testament to the critical importance of childhood cancer research, especially for rare and hard-to-treat cancers.

Callen, you’re a little legend. Let’s give cancer a real butt-kicking for Callen this September!