Harriet Green, CEO of Thomas Cook, says her approach to business has been shaped by the loss of her father to brain cancer when she was just 14 years old. That gave her the courage and perspective to take on the challenge of turning around the Thomas Cook brand. "When you're a child and your family's quite dominated by cancer, the worst that could happen has kind of happened," she says. "What's the worst that could happen [in my career]? I fail. But is that lymphoma or leukemia? No."