Stem cell tensions.

This article reports that researcher Chris Shaw and his colleagues at King's College London, England, said that it might be possible to derive stem cells from embryos cloned using rabbit eggs. One team, led by Hui-Zhen Sheng at the Shanghai Second Medical University in China, claims to have already succeeded in taking embryonic stem cells from such rabbit-human "embryos." But now Bob Lanza of Advanced Cell Technology in Worcester, Massachusetts, has raised doubts about the procedure, since no one has been able to replicate Sheng's results.