Each of them fitting one possible guest at the dinner party, which in this case is an antigen from a microorganism that could invade your body. So through controlled recombination, your immune system is prepared for every possible antigen an enemy could make. But there is a catch—this ingenious way to create such stunning variety makes your adaptive immune cells critically dangerous to you. Because what is stopping them from developing receptors that are able to recognize self, the parts of your own body? Well, their education is.
