Some tissue types are more common in certain ethnic groups of the population, meaning that a patient is more likely to be matched with a donor from a similar ethnic background. This also increases the chances of a successful transplant.
The UK population is made up of people from many different ethnic communities. This wide range of tissue types may help to find potential stem cell donors for new patients who need transplants, both here in the UK and overseas.
You are especially needed as a stem cell donor if you are from an African, African-Caribbean, Asian, Chinese, Jewish, Eastern European or Mediterranean community.
More top news
CCTV and images show man suspected of trying to set the north London mosque alight in alleged Islamophobic hate crime
Detectives investigating a man's body washed up on the shores of the river have arrested a second man on suspicion of murder.
Keepers have the celebrating the arrival of the western lowland gorilla to 22-year-old mother Effie in captivity at the zoo.