Question: I heard that stem cells helped grow a human ear on the back of a rat is this true or just a myth????

Jeremy Green answered on 14 Jun 2011:

Kind of gross, isn’t it? This is sort of a myth. There is a famous picture of an “ear” growing on the back of a mouse, but this is in fact not an ear but a piece of cartilage grown and shaped in a dish and grafted under the skin of the mouse. This was done to demonstrate tissue engineering – making artificial organs or tissues from cells grown in dishes. This could be really useful for, say, some child mauled by a dog and needing a new ear. (Almost all parts of the body have some stem cells in them, including skin and cartilage, but that’s probably not the kind of stem cell you mean, which is an embryonic stem cell.)