Elevated levels of PTHrP were reported in a number of clinical myeloma cases, and recent studies by Cafforio et al. have found that both the full-length molecule and NH2-terminal fragment of PTHrP reinforces the production of osteoclastogenic factors RANKL and MCP-1, thus activate osteoclastogenesis [38]. This evidence concerns the gene TNFSF11 and plasma cell myeloma.