Science blog (Clive Cookson): Embryonic stem cells get all the publicity in stem cell research, good and bad. Their supporters see them as the future of regenerative medicine, producing all manner of new human tissues to treat degenerative diseases. Opponents - mainly from religious groups - hate that they originate with the destruction of an embryo.

No treatment based on human embryonic stem cells has yet been tested on patients, although the US Food and Drug Administration recently told Geron that it could begin a clinical trial of embryonic stem cells to treat spinal injury. Meanwhile, as the UK national stem cell conference in Oxford heard on Monday, universities are making good progress using adult stem cells, derived from the patients themselves, to repair bone and cartilage.