ACP5 and breast carcinoma: After analyzing images from each condition, we found that the surface size of TRAP-positive osteoclasts produced in the presence of MDA-MB-231 breast cancer cells plus EO-231 cells was significantly reduced (57%) compared to the surface size of TRAP-positive osteoclasts produced in the presence of MDA-MB-231 breast cancer cells plus naïve osteoblasts (Figure 5d).