A Winnipeg family is urging people to become stem cell donors, in the hopes that someone can help their 13-year-old daughter overcome leukemia.

Alex Blake is fighting leukemia at Children's Hospital, and her family is hoping for a stem cell donor who could be a match.

"That perfect match might be across the street, so we're just appealing to people to get their blood tested," Stuart Blake, her father, told CBC News.

Last year, the Grade 8 student had Ewing's sarcoma, a form of bone cancer.

Alex underwent surgery, followed by chemotherapy from June to October, and she received a clean bill of health afterwards, Blake said.

Then this month, Alex was diagnosed with acute myeloid leukemia, "which is likely caused by one of the chemotherapy drugs that she had to take to fight the bone cancer," her father said.

Blake said his daughter has already had several days of chemotherapy in hospital, with the goal of getting the cancer into remission.

The teen needs a stem cell transplant in order to develop a new immune system and ensure her long-term survival.

However, it has not been easy to find a matching donor: Blake said Alex's doctor has indicated she has a human leukocyte antigen (HLA-A) type that is fairly rare.

Anyone between the ages of 17 and 50 can join the Canadian Blood Services' OneMatch stem cell and marrow registry.

Interested donors can log on to the Canadian Blood Services' website and follow the "What can I donate?" link to "Stem cells" for information on how to register.