Chinese researchers are reporting new steps in the quest for animal-to-human organ transplants – with a successful pig kidney transplant and a hint Wednesday that pig livers might eventually be useful,

Doctors in China have become the first to report details about a transplant of a genetically modified pig liver into a human.

The trial was part of a small — but growing — group of animal-to-human organ transplants, in a practice known as "xenotransplantation".  But will pig livers eventually replace human organ transplants?