Sometimes there are lessons to be learnt even from villains.
Viruses are spectacularly, often fatally, successful at invading cells.
Now, by adapting a trick used by the AIDS virus HIV, a team of US chemists has found a new way to smuggle drug molecules through cell walls. Cells are designed to exclude would-be invaders. They are enclosed in a membrane of fatty molecules, through which molecules that dissolve in water cannot pass easily. HIV has solved this problem all too effectively. Like other viruses, it hijacks the machinery that a cell uses to replicate, so that the cell makes new viruses instead.