How immune cells 'sniff out' bacteria

How immune cells 'sniff out' bacteria: "(Society for General Microbiology) Scientists are learning how our immune system senses and tracks down infection in the body by responding to chemical 'scents' emitted by bacteria. Studying how immune cells manipulate their movement in response to external signals could shed light not only on how our immune system functions but also how cancer cells spread through the body and even how the brain wires itself."