Stem cells have the unique and defining characteristics of unlimited self-renewal and the capacity to differentiate into progeny cells of specialized function. During the course of human embryonic development and throughout the adult lifespan, stem cells play pivotal roles in the establishment and ongoing repair of virtually all organs systems.  Impairment of normal stem cell function can result in birth defects, tissue degeneration, and even cancer.  Thus, it is essential to develop a detailed understanding of the molecular basis by which stem cells regulate the processes of self-renewal and differentiation.  At the Genome Institute of Singapore we are working with adult, embryonic, and cancer stem cells to unravel the complex networks that control these states and to understand how misregulation can lead to disease.  To this end we are combining expertise in cell biology, developmental biology, genomics technologies, genetics, and bioinformatics to dissect the regulatory systems that control stem cell function.