Researchers have successfully used stem cells to grow mouse kidneys inside rats.

In a study with significant implications for human organ transplantation, researchers have successfully grown functional mouse kidneys inside rats from just a few donor stem cells.

For patients with end-stage renal disease, a kidney transplant is the only hope for regaining quality of life. Yet many of these patients will never undergo transplant surgery thanks to a chronic shortage of donor kidneys. Demand far outstrips supply.

But researchers have been working on ways to grow healthy organs outside the human body. 

Initial attempts by the researchers to grow rat kidneys in mice proved unsuccessful, as rat stem cells did not readily differentiate into the two main types of cells needed for kidney formation. However, when the reverse scenario was attempted the scientists had more success.