Policy: Regulate Embryos Made for Research

Three independent research teams have now used cloning technology to make human embryonic stem cells carrying the genomes of existing people. The first announcement, using genomes from fetal and infant cells, came last year1. The next two reports have emerged in the past month, detailing human embryonic stem cells that were custom made from cell samples derived from living adults, including a 75-year-old man2 and a 32-year-old woman with type 1 diabetes3.

This repeated cloning of embryos and generation of stem cells, now using cells collected from adults, increases the likelihood that human embryos will be produced to generate therapy for a specific individual. The creation of more human embryos for scientific experiments is certain. Regulatory structures must be in place to oversee it.

These accomplishments were made possible by numerous tweaks, and by mastery of difficult techniques and of the administrative work required to collect enough eggs from healthy young women. Each research team inserted nuclei taken from human skin cells into unfertilized eggs from which the original nuclei had been removed. These constructions...