So this is our bone, this is the bone marrow. And inside the bone marrow, our hemopoetic stem cells essentially form red blood cells. Those red blood cells mature, they end up being released into our blood plasma. So red blood cells are released into our blood. Now, after about 120 days of circling our cardiovascular system, they essentially are damaged to the point where they either lice directly in our blood or they go into our spleen, into our liver or end up in the lymph nodes. And the white blood cells engulf those damaged red blood cells and form this vacuole inside that combines with the lysosomes of the macrophage.