US scientists have created working liver grafts in the lab, and say the research could one day allow the growth of livers for transplant.
There is a shortage of liver donors, but so far it has been difficult to grow replacement organs.
In the work, published in Nature Medicine, a team from Massachusetts General Hospital, created successful grafts using rat cells.
A UK expert said it was “a big step in the right direction”.
In the study, scientists initially flushed out living liver cells, leaving behind a tissue “scaffold”.