Much of the stem cell research community is engaged in determining the recipes needed to create large numbers of specific types of cell for specific therapeutic uses. There are a few hundred different types of cell in the human body, so you'll periodically see announcements such as this as successes are achieved:
A new approach for generating large numbers of circulatory system cells, known as vascular endothelial cells (VECs), from human amniotic-fluid-derived cells (ACs) is reported ... The strategy, which shows promise in mice, opens the door to establishing a vast inventory of VECs for promoting organ regeneration and treating diverse vascular disorders.
VECs line the entire circulatory system, including the heart and blood vessels, and they help to control blood pressure, promote the formation of new blood vessels, and support the regeneration and repair of injured organs. A wide range of vascular diseases stem from dysfunctions in VECs, so generating healthy cells for transplantation in patients would represent an attractive treatment strategy. But past stem cell strategies have fallen short: VECs derived from stem cells are unstable and tend to convert to nonvascular cells, and they do not increase rapidly in number, limiting their potential for clinical use.
To overcome these limitations, [researchers] developed a safe approach for producing a large number of stable VECs from amniotic cells, which are extracted during routine amniocentesis procedures and thus represent a steady source of cells. To reprogram amniotic cells into mature and functional VECs, called rAC-VECs, the researchers turned specific genes on and off using members of the E-twenty-six family of transcription factors - proteins that bind DNA and are important for VEC development.
The rAC-VECs resembled human adult VECs in that they expressed the normal set of vascular-specific genes. When rAC-VECs were transplanted into the regenerating livers of mice, they formed stable, normal, and functional blood vessels.