So this is our bone. We have the lining of the bone and these are the cells found on the lining of that bone. Now, let's suppose we want to actually recruit certain cells, the osteoclast, to a certain location to break down that bone. So we basically activate these osteoclasts, we recruit them and we signal exactly where we want our rebuilding process to take place. Remodeling process to take place. Let's suppose it's here.