The co-cultures from Figure 5D and 5F were processed for RNA isolation and analyzed by Q-PCR with mouse-specific primers for bone markers: RANKL, the central regulator of osteoclastogenesis (Figure 6A) and tartrate-resistant acid phosphatase (TRAP) a major osteoclast enzyme (Figure 6B) were increased by myeloma cells. Here, ACP5 is linked to plasma cell myeloma.