ACP5 and neoplasm: Tumor-bearing rats also had a 4.6-fold increase in trabecular bone surfaces lined by TRAP-positive osteoclasts (36.6 ± 21.6 × 10−3 vs. 7.9 ± 6.5 × 10−3 TRAP-positive surface/total bone surface, P = 0.009, n = 14, Fig. 4h–j).