There was not a dry eye in the house when a teen battling an ultra-rare form of childhood cancer opened a package to reveal that her siblings were a perfect bone marrow transplant match. Megan Mejia's unique "Bone Marrow Match Reveal" was born out of extreme unlikelihood, but her family viewed it just like any viral gender reveal party: a celebration of new life and hope. Thirteen-year-old Megan was diagnosed with Acute Lymphoblastic Leukemia, a common form of childhood cancer, in August 2021 – but her family later learned that Megan actually had a rare subtype that is resistant to all chemotherapy and is found in just one percent of all children with leukemia. As a result, Megan is currently undergoing a fairly new and groundbreaking treatment for hard-to-treat cancer, known as CAR-T immunotherapy, after which she will undergo a bone marrow transplant to stop the cancer from returning. On December 12 at Megan's Bone Marrow Match Reveal Party, the teenager opened the package at her grandparents' house in Ontario, California.