LAUSR

Purpose of reviewTo summarize and clarify the main ethical issues surrounding the generation and use of human-animal chimeras in stem cell research.Recent findingsUS federal funding remains restricted for certain forms of human-animal chimera research despite the widespread promulgation and acceptance of national and international stem cell-specific research guidelines.SummaryStem cell-based human-animal chimera research can promote advances in basic human developmental biology, disease modeling, and new drug discoveries. National and international guidelines for this form of stem cell research have been developed over the past several years but ethical concerns persist around human dignity and the possible moral humanization of chimeric animals. These concerns can be defused and ought to be replaced with a more tractable focus on animal welfare.