For many blood cancer patients, a blood stem cell donation from a suitable donor is their only chance of survival. The blood stem cells are removed from the donor and implanted in the recipient – in a stem cell transplantation. The new, healthy blood stem cells help the recipient’s bone marrow to regenerate and produce healthy blood cells again. But for this to work, the donor and recipient must have exactly the same HLA markers. You could be the perfect match for a patient somewhere in the world – and help them sometime soon!