Teresa Jiménez is a hematologist and medical director of the Blood Bank at the Blood and Tissue Bank Foundation of the Balearic Islands. She has witnessed firsthand the change in the recruitment of marrow donors in the Balearic Islands: from 44 new registrations in 2023, they went to 545 in 2025. Despite this increase, more are still needed, especially young people and those of diverse backgrounds. Jiménez explains what it means to join the Bone Marrow Donor Registry (REDMO), how compatibility is checked, and what happens if, years later, the call comes.