While it may take another 10 years before lab-grown livers could be used to treat patients, the Japanese scientists say they now have important proof of concept that paves the way for more ambitious organ-growing experiments.

"The promise of an off-the-shelf liver seems much closer than one could hope even a year ago," said Dusko Illic, a stem cell expert at King's College London who was not directly involved in the research but praised its success.

He said however that while the technique looks "very promising" and represents a huge step forward, "there is much unknown and it will take years before it could be applied in regenerative medicine."