Tissue engineering tries to use the self-healing characteristics of biological tissues to regenerate and restore organ function. To do so, cells from various origins, growth-inducing chemicals, and a biomaterial-support termed a scaffold are utilized alone or in combination to reconstruct organs. However, regenerating a functional tissue or organ has proven difficult. With recent advancements in adult and embryonic stem cell technologies, the fantasy of regenerating a full organ, or at least sections of it, appears to be closer than ever.