Vitamins and supplements like zinc and cod liver oil are often touted for their ability to boost your immune system, but Jeffrey Bland, the "father of functional medicine," says that's not actually ...

Imagine a high-tech security system, constantly scanning for intruders, identifying threats, calling for backup, neutralizing them, cleaning up the mess, and keeping detailed records for next time.

How does the same infection, say the flu or a cold, give some people mild symptoms and leave others suffering? Why do people develop autoimmune diseases? And will we ever be able to predict when—and ...