One of the most uplifting superhero tales starts in a children’s hospital in Philadelphia, Pennsylvania, with four year old Michael DeMasi Jr. running through the halls, asking his mother to get him a balloon so he would be able to fly. The boy was surprisingly excited for what would likely be a scary operation: a needle being pushed into bone by his hip in order to extract bone marrow.

The motive behind Michael going through this is undeniably pure– the bone marrow would be donated to his four month old twin brothers who had Chronic Granulomatous Disease (CGD). This disease means that the immune system of those infected is fragile, and something as miniscule as a cold could be life threatening. DeMasi’s nine year old brother also suffered from CGD, but he was put on a bone marrow transplant list shortly after he was diagnosed as a baby and received stem cells from a donor.

When the young twins were diagnosed, Michael was found to be a match after some testing. His parents explained to him what that meant, and how it would benefit his brothers if he chose to donate bone marrow.

“We were straight up — ‘It’s going to be a big needle going into your back, bud.’” mother Robin Pownall said. “We asked him, ‘Do you want to do this? If you’re scared, you don’t have to.’”

Michael asked if his donation would help his brothers come home soon. When his mother said yes, he immediately agreed to give his bone marrow to the twins.

Both the marrow extraction and transplants into the twins went extremely well, and now at seven months old both twins show no signs of CGD, though doctors are still monitoring them closely.

An enchanting (albeit quite short) chat between Michael and an interviewer from the Washington Post shows the charm of the four year old. The reporter introduced herself and asked the boy what he had done to help his younger brothers.

“I saved them because I’m a superhero!” Michael said.

Upon a few further questions, Michael said that he felt good that the transplant was successful and that he was excited for his brothers to be home.

Proved by his truly heartwarming story, Michael DeMasi Jr. definitely qualifies as a superhero.