This time, Kate Quilton and Tamal Ray investigate the subjects of pain and disease. They look into the latest scientific approaches for growing bone; the alleged curative effects of echinacea; and some of the latest surgical approaches to treating back pain. Lower back pain is thought to affect around one third of the UK population. This time, the big experiment finds out whether osteopathy, physiotherapy or yoga can help. Meanwhile, journalist Morland Sanders delves into the world of online DNA testing kits and the risks you might like to consider before sending off a sample of your saliva.