Corey Halliday looks like an ordinary 13-year-old.

But behind his cheeky grin is an extraordinary teenager, born with a one-in-a-million illness that threatens to cut him off from the world.

Corey is one of a handful of Australians diagnosed with Kostmann’s Syndrome, a severe congenital disease that means his body cannot fight bacterial infection.

Paper cuts, colds and mosquito bites have all put Corey in hospital – he has been admitted about 80 times – because he does not produce the white blood cells needed to battle illness.

When Suzanne Penney was diagnosed with leukemia after she battled breast cancer, she decided to undergo an injection of umbilical stem cells – and the procedure saved her life, KNSD-TV reported Thursday.

Penney, who lives in Carlsbad, Calif., contracted leukemia as a result of the aggressive chemotherapy she received for her breast cancer.

“When information about stem cells first came out I was against it,” Penney told KNSD-TV. “I always thought, ‘don’t mess with Mother Nature, and there’s going to be a bunch of cloned people walking around.’”

But, today, as Penney recovers in the hospital, doctors tell her that her leukemia is in remission.