When the back pain Hannah, now 12, had been experiencing for a month became so bad she could barely move, her parents, Rachel and Hugh McStay, rushed her to The Children's Hospital of Philadelphia’s Emergency Department. The doctors who examined Hannah found several compression fractures in her spine. The cause? Leukemia, which had created lesions on her spine and weakened her bones.

With an initial diagnosis of standard-risk acute lymphoblastic leukemia, Hannah began a regimen of chemotherapy and underwent lumbar punctures that would deliver the cancer-fighting medicine directly into her spinal fluid. But two weeks into treatment, a genetic test indicated Hannah had a very high-risk form of leukemia called hypodiploid. The diagnosis meant more intense chemotherapy and a search for a match for a bone marrow transplant.

After five months of therapy that included total body irradiation and very high-dose chemotherapy, Hannah was ready for the bone marrow transplant. “Her stem cells were donated by an anonymous donor, which we are forever thankful for,” says Rachel.

The transplant worked to rid Hannah’s body of leukemia, and she has been cancer-free for more than three years. But she paid a price: The treatment caused graft-versus-host disease, a chronic condition that is kept under control with medication.

Although Hannah hasn’t been able to resume the soccer she once loved to play, she has a dance teacher who works around the muscle and bone weakness brought on by the disease and treatment. “It gives me so much joy to see her continue to do something she loves,” says Rachel. Hannah’s most important outlet is art, and she’s prolific: “There’s not much time that goes by that Hannah isn’t working on some sort of piece of art,” her mom reports.

Hannah’s family is looking forward to being part of the Parkway Run & Walk on Sept. 25, and they’ve named their team Hannah’s Fighters. The event benefits pediatric cancer research and care at The Children’s Hospital of Philadelphia, and this year Hannah is a Patient Ambassador. The contributions that Hannah’s Fighters make to the Cancer Center will help researchers develop new treatments that are more effective and come with fewer side effects, so kids like Hannah can spend less time feeling sick and more time just being kids.

“There are so many times staff members at CHOP have gone above and beyond,” says Rachel. Now, Hannah’s Fighters are ready to do the same for CHOP.