<http://schema.org/description>
"There are millions of bacteria, microbes, viruses, toxins and parasites that want to invade your body. And they&amp;#039;d happily do it, too -- if it weren&amp;#039;t for your immune system."^^<http://www.w3.org/2001/XMLSchema#string>
<http://health.howstuffworks.com/human-body/systems/immune/immune-system2.htm/printable>