Search for missing swimmer suspended; witness saw shark with body in its mouth Johnny Carson book exposes 'Tonight Show' ban list featuring Jay Leno, Ellen DeGeneres Dread, tears as Tyson plans to lay ...

Stem cells are precursors of a variety of different cells: They can turn into anything from blood to bone to muscle. Human blood stem cells, known as hematopoietic stem cells, are the forerunners of ...

A vivid new image is taking shape in the world of cell biology: Imagine bacteria adhering to the surface of a cell, perhaps at the site of an injury or wound. In response, a white blood cell arrives ...