Ten years ago a new dawn beckoned for science. The $4 billion dollar Human Genome Project was complete– the book of life was open, the secret code of DNA had been cracked. But where are we now? Horizon follows three people who hope the mapping of the human genome will transform their lives.

Sophie is 21 and has cystic fibrosis, a long-term, ultimately fatal disease of the lungs and pancreas. She has a life expectancy of just 35. Her journey sees her meet a child who, against the odds, was cured of his terminal illness with gene therapy. Though this currently doesn’t work for CF sufferers, she meets scientists dedicated to finding a cure for her illness.

Tom, a 35-year-old recovering alcoholic, wants to know if his alcoholism can be explained by his genes. He visits a lab where mice have been bred with a genetic predisposition to alcoholism. Could genes be the voice in your head telling you to have another drink?

In the past six years, Emma, 35, has been diagnosed with three types of cancer and undergone grueling surgery and chemotherapy. Now a mother, she is faced with the prospect of her son getting cancer in the future and wants to know how far away an effective treatment really is. She meets scientists working on a revolutionary approach to treating cancer. Trials have shown it to be incredibly effective, but so far it only treats one rare form of the disease – the one Emma suffers from.