And what we want to do is, since we want to produce a specific type of antibody, what we're going to do is we're going to inject that mouse with an antigen that binds to that antibody that we want to study. And so if we inject the antigen into the bloodstream of that mouse, the immune system of that mouse will begin to produce the plasma cells that produce the antibodies that bind to that antigen. So after time, when this mouse has those plasma cells, following injection, we can basically draw blood, let's say, from the spleen. And if we draw the spleen cells, because in the spleen cells, we have a high concentration of these plasma cells, some of these plasma cells in the spleen will basically contain the ability to produce that specific type of antibody. So we inject the antigen into our mouse, and we wait some time until that mouse produced our plasma cells that produce the antibody of choice. And so then we essentially draw some blood from our spleen, from the spleen of that mouse and we extract those spleen cells.