Progress in tissue engineering: "scientists have created human kidneys from stem cells ... The artificial organs were created in a laboratory using human amniotic fluid and animal foetal cells. They are currently half a centimetre in length - the same size as kidneys found in an unborn baby. [Scientists] hope they will grow into full-size organs when transplanted into a human. ... It sounds a bit science fiction-like but it's not. The idea is to start with human stem cells and end up with a functioning organ. We have made pretty good progress with that. We can make something that has the complexity of a normal, foetal kidney ... The research team hope that doctors will eventually be able to collect amniotic fluid, which surrounds the growing embryo in the womb, when a baby is born. This will then be stored by scientists in case that person develops kidney disease later in life. The fluid can then be used to create a matching kidney. Creating an organ using a patient's own stem cells solves the problem of having to use powerful immunosuppressant drugs to stop the body rejecting a another person's kidney. ... the technology could be ready for use on humans in around 10 years." By which time it will probably be unnecessary to collect amniotic fluid, as the signals and chemicals it provides will be understood and reproduced.