Frontiers of Pluripotency.- Highly Efficient Derivation of Pluripotent Stem Cells from Mouse Preimplantation and Postimplantation Embryos in Serum-Free Conditions.- Derivation of Hematopoietic Stem and Progenitor Cells from Human Pluripotent Stem Cells.- Cancer Stem Cells: Concepts, Challenges and Opportunities for Cancer Therapy.- Informed Consent Issues for Cell Donors.- Chick Models and Human-Chick Organizer Grafts.- The Engraftment of Lentiviral Vector-Transduced Human CD34+ Cells into Humanized Mice.- Pig Chimeric Model with Human Pluripotent Stem Cells.- Embryonic Chimeras with Human Pluripotent Stem Cells.- Neural Stem Cell Transplantation into a Mouse Model of Stroke .- Ethical Standards for Chimera Research Oversight.- Ethical Considerations in Crossing the Xenobarrier.- Neurological Chimeras and the Moral Staircase.- Isolation, Cryopreservation, and Transplantation of Spermatogonial Stem Cells.- Human-Monkey Chimeras for Modeling Human Disease: Opportunities and Challenges.