There are trillions of cells in the human body, and they all have to work hard to keep that body alive. But what if that body isn't taking great care of itself? What if that body smokes too much? Or drinks too much? What if that body forgets to use protection? Why, it might find itself with all manner of dysfunction, and who's going to have to pick up the pieces? It turns out the same immune cells that fight off the common cold also have to deal with troubles of a distinctly more adult nature. . .