It is ethical to transplant human stem cells into nonhuman embryos
Human/nonhuman stem cell chimeras will be increasingly applied to study human cells in developing nonhuman animals. Such experiments raise a number of issues that may create further controversy in the stem cell field. Here we outline the scientific value and ethical ramifications of such studies, and suggest how such experiments may be conducted ethically.
Karpowicz, Phillip; Cohen, Cynthia B.; and van der Kooy, Derek, "It is ethical to transplant human stem cells into nonhuman embryos" (2004). Nature Medicine, 10, 4, 331-335.