On the third Saturday of September every year, the whole world celebrates Bone Marrow Donor Day. The purpose of this day is to honor those people who risk their health to save the lives of patients with leukemia. Also, this holiday draws attention to information campaigns and encourages becoming donors of hematopoietic stem cells.

Until the second half of the 20th century, leukemia and lymphoma were considered incurable diseases. Everything changed when Donnal Thomas performed a successful bone marrow transplant in 1969, for which he was awarded the Nobel Prize. Nowadays, the number of such operations per year worldwide is approximately 50,000.

To carry out such treatment, a donor is needed who agrees to give a certain amount of his hematopoietic stem cells from the bone marrow. Cell selection takes place over several hours under endotracheal anesthesia. After that, the person needs medical rehabilitation. But, despite all possible risks and unpleasant feelings, there are about 5 million such donors registered in the world.