Petrozavodsk is a small town at Lake Onega, the second largest lake in Europe. Here is situated one of the first register of unrelated donors of hematopoietic stem cells in Russia– Karelian department. The effectiveness of the register is the great merit of volunteers. There is one special person among all volunteers. Her name is Natasha Kovaleva. This fragile young woman has fought off leukemia thanks to the Karelian register of unrelated donors of hematopoietic stem cells and now helps others. For the first time the disease crippled Natasha when she was 21. It all started with the common cold,…