This will give you a flavour of the story - follow the link for the rest of it:
At the age of nine few children know what they will go on to do with their lives. But for a scientist involved in one of the most revolutionary medical operations of recent times, his destiny appears to have been spelled out in a letter written 35 years ago, to a BBC children's programme.
It had been a heck of a year for Professor Anthony Hollander. In 2008, after 20 years of research into helping arthritis sufferers he unexpectedly found himself being asked to urgently adapt his skills to help save the life of a woman in Spain.
The groundbreaking treatment, by a team of scientists and surgeons, gave the woman a new windpipe using her own stem cells. He had helped save a dying woman and the successful operation made headlines around the world. It was, by any measure, a career high.
After it was all over Mr Hollander got to thinking, and suddenly made a connection. In 1973, a nine-year-old Anthony Hollander had written to Blue Peter to tell them he had a "strange" belief that he knew how to "make people or animals alive".
The letter, which by his own admission today was "eccentric", went on to ask the programme to help him acquire the necessary materials to carry out these life-saving tasks.
The shopping list included a "model of a heart split in half" and "tools for cutting people open".
Thousands of children wrote to the programme every week, but each one received a personal letter back, and Anthony was no exception.
The response from then editor, Biddy Baxter, was "fundamental" to his future, he now believes. She encouraged him to seek information for his idea from the family doctor.
It was not so much the advice itself that left an impression on the boy. It was that whisper of encouragement that he gleaned from having received a reply at all, and that the letter did not dismiss his idea.
"If her letter had shown any hint of ridicule or disbelief I might perhaps never have trained to become a medical scientist or been driven to achieve the impossible dream, and really make a difference to a human being's life," he says.
You can read the rest of the story here. Oh, and I just looked the guy up, and he's had a lot of success in his research with ADULT stem cells. Just so you know...