Image courtesy of Dr. Nate Manley of Asterias Biotherapeutics. Description: In this photomicrograph, cultured H1 human embryonic stem cells are fluorescently labeled to show their cytoskeleton (green), nuclei (blue), and expression of the pluripotency marker, SOX2 (magenta). Pluripotent stem cells are defined by their ability to self-renew and become any cell type found in the body. The capacity of these cells to generate virtually unlimited amounts of diverse cell types offers unprecedented therapeutic potential.