Cell self-renewal and the capacity to differentiate into multiple cell types (pluripotency) are biological attributes casting stem cells as attractive candidates for development of therapies targeting indications that involve functional restoration of damaged tissues. In the United States, clinical trials designed to demonstrate the safety and effectiveness of stem cell-based products are regulated by the U.S. Food and Drug Administration (FDA). To ensure that subjects enrolled in a clinical study involving stem cell-based products are not exposed to significant and unreasonable risk, the FDA reviews medical and scientific information that encompasses delineation of product-specific characteristics and preclinical testing to determine whether there is sufficient safety assurance to permit initiation of human clinical studies.