CELL OR CELL-BASED TISSUE ENGINEERING therapy is a rapidly growing and evolving technology that can include a broad range of products, e.g., processed, selected, or expanded human or other mammalian cells, stem or progenitor cells, genetically engineered cell therapies, alone or in combination with a synthetic or biological biomaterial. The United States Food and Drag Administration (FDA) reviews and regulates these products to assure safety and effectiveness. Beginning in the 1990s, the FDA has set forth a considerable amount of resources to improve the review and regulation of these products to ensure the protection of the public health while permitting significant innovation and keeping regulatory burden to a minimum. Currently, the FDA has approved some cell-based tissue engineered products for use, whereas others are still in preclinical development or undergoing regulatory evaluation.