Continuing the infrastructural bioscience theme, ScienceDaily notes new knowledge that will lead to greater and more effective control over totipotent stem cells: "Our study suggests that what we believe about how embryonic stem cell self-renewal is controlled is wrong. Our findings will likely change the research direction of many stem cell laboratories. ... Contrary to the current understanding of stem cell self-renewal and differentiation, the findings suggest that embryonic stem cells will remain undifferentiated if they are shielded from differentiation signals. By applying small molecules that block the chemicals from activating the differentiation process, the natural default of the cell is to self-renew, or multiply, as generic stem cells. ... This study presents a completely new paradigm for understanding how to grow embryonic stem cells in the laboratory. The discovery has major implications for large scale production of specialized cells, such as brain, heart muscle and insulin producing cells, for future therapeutic use." Replacing cells lost to aging is one important part of any suite of longevity therapies, and advances that bring that goal closer are welcome.