MONTREAL - Call them blood sisters.

They may be complete strangers of different ages and from different countries, but Marjorie Troia and Sabrina Leblond-Murphy are a perfect match.

"We share the same blood, but even sisters don't share the same blood," explained Leblond-Murphy. "They have similar blood, but we have identical blood."

Leblond-Murphy was diagnosed with leukemia two years ago at 26. The odds of finding a blood match were 1 in 750,000, and without it, the chance of survival was slim.

But ten years ago in Colchester, Vermont, Troia had registered on the bone marrow donor list.

She knew she had to help.

"If anyone was told, ‘You have something that can save somebody's life,' I don't think anyone would say no. I feel like I am truly lucky to have been part of this," she said.

Troia said she's no hero, but was instead amazed by Leblond-Murphy's strength, something Dr. Sandra can attest to.

"She's always taken it in stride. I have never seen her complain. She's really an amazing patient, I would have to say," said Cohen.

Two years and many cross-border visits later, the two have become close friends, who now share blood, but also fun.

"It was very comfortable the second we met, I felt like I had known her forever," said Troia.

And that close bond has literally been a lifesaver.

"There's no way we could thank her enough, obviously. To us, to have given us back our daughter, is so wonderful," said mother Marie-Pascale Leblond.

Leblond-Murphy is in remission, with Troia to thank.

"Without Marjorie," said boyfriend Luke Mikelsons, "it'd be a pretty different story right now."