It is still hard to believe that manipulation of a single protein on the cell surface or an interaction of two or more proteins, which at times is collectively referred to as a pathway, could have such a profound effect on our immune system. At present, a number of such proteins or pathways have been identi?ed. These observations could only be interpreted in a way that, although tens of thousand of proteins are required for a perfectly healthy immune system, many of these pathways may work in either interconnected or linear fashion. Therefore, the combined understanding of each pathway, their...