From the Telegraph, news of continuing incremental progress in understanding the mechanisms of regeneration in lower animals: "research into how Planarian worms can regrow body parts - including a whole head and brain - could one day make it possible to regenerate old or damaged human organs and tissues ... We want to be able to understand how adult stem cells can work collectively in any animal to form and replace damaged or missing organs and tissues. ... Any fundamental advances in understanding from other animals can become relevant to humans surprisingly quickly. If we know what is happening when tissues are regenerated under normal circumstances, we can begin to formulate how to replace damaged and diseased organs, tissues and cells in an organised and safe way following an injury caused by trauma or disease. This would be desirable for treating Alzheimer's disease, for example. With this knowledge we can also assess the consequences of what happens when stem cells go wrong during the normal processes of renewal - for example in the blood cell system where rogue stem cells can result in Leukaemia."