Peering deep within the cells of fruit flies, developmental biologists at the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia may have discovered a new way that genes are turned on and off during development. If they're right, and the same processes are at work in higher organisms, including mammals, the findings could eventually have implications for improving the understanding of a range of diseases, including childhood cancer.

Stem cells grew, multiplied and differentiated into brain cells on a new three-dimensional scaffold of tiny protein fragments designed to be more like a living body than any other cell culture system.

The incidence of stroke in the U.S. over the past 50 years has declined, although the severity of stroke has not, according to a study in the December 27 issue of JAMA.

If a zebrafish loses a chunk of its tail fin, it'll grow back within a week. Like lizards, newts, and frogs, a zebrafish can replace surprisingly complex body parts. A tail fin, for example, has many different types of cells and is a very intricate structure. It is the fish version of an arm or leg.