Liver donor, recipient running New York City Marathon together

Among the 33,000 runners in the 50th New York City Marathon Sunday will be two friends with an uncommon bond. It will be a celebration of life for Sara Kate Gillingham and Dave Kane.

"It's really nice to be able to sit here and smile and laugh about it. But it was a very dark time," says Gillingham.

That dark time dates back more than four years, when Kane was fighting for his life. "The diagnosis was pretty grim," he says.