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. Now, the majority of these spleen cells will not have the ability to actually build that antibody of choice, but some of these will be the plasma cells that produce the antibody of choice. And so, as we'll see in step three, we're going to want to screen these different types of plasma cells and we want to find those plasma cells that basically produce that particular antibody of interest. Now, in the second step, what we want to do is now we want to transform them into cancer cells.