NIH Considering Human-Animal Stem Cell Research

Last week, the National Institutes of Health (NIH) announced plans to end its longstanding ban on funding research that involves injecting human stem cells into animal embryos, where they can be made to grow into any kind of cell. The main purpose of these experiments is to grow human tissues and organs inside the bodies of genetically altered animals to better understand human diseases and improve treatments for them. While this could potentially advance the medical field, it also raises serious ethical concerns. For example, the practice could lead to growing human organs inside animals for transplant to people or injecting human cells directly into animals’ brains. This latter possibility is particularly problematic because, as University of California, Davis stem cell researcher Paul Knoepfler told The New York Times, “…we lack an understanding of at what point humanization of an animal brain could lead to more humanlike thought or consciousness.” The NIH will likely announce its final decision this fall following a 30-day public comment period.