What happens to a stem cell at the molecular level that causes it to become one type of cell rather than another? At what point is it committed to that cell fate, and how does it become committed? The answers to these questions have been largely unknown. But now, in studies that mark a major step forward in our understanding of stem cells' fates, a team of researchers from the California Institute of Technology (Caltech) has traced the stepwise developmental process that ensures certain stem cells will become T cells—cells of the immune system that help destroy invading pathogens.

Abandoned army bunkers along the Jordan River have become a habitat for 12 indigenous bat species, three of which are already designated as endangered and two that are on the critical list. The bats were recently identified by a group of Tel Aviv University researchers who were granted access to the bunkers, spread out along a 60-mile-long stretch of land between the Sea of Galilee in the north of Israel to the Dead Sea's northern edge.

A team of researchers at Case Western Reserve University School of Medicine have identified a new mechanism by which colon cancer develops. By focusing on segments of DNA located between genes, or so-called "junk DNA," the team has discovered a set of master switches, i.e., gene enhancer elements, that turn "on and off" key genes whose altered expression is defining for colon cancers. They have coined the term Variant Enhancer Loci or "VELs," to describe these master switches.