So our wide blood cells of our immune system are naturally immunologically tolerant to the healthy cells of our body. And what that means is these wide blood cells will not attack the healthy cells of our body. Why is that? Well, because our healthy cells produce induced proteins called self antigens and they display these self antigens on special protein complexes found on the membrane of those healthy cells and they display these antigens to wide blood cells. So when a wide blood cell sees a self antigen on a healthy cell, it will not attack that healthy cell. So under normal and healthy conditions, our immune system has no problem distinguishing between these self antigens found on healthy cells and pathogenic antigens found on infected cells or on invading pathogens such as bacterial cells.