Tumor cells secrete factors such as Parathyroid hormone-related protein (PTHrP), IL-6, IL-11, and Prostaglandin (PG)E2, which induce Receptor activator of NF-κB ligand (RANKL) expression in osteoblasts and thereby promote osteoclast differentiation, supported by in vitro and in vivo models [60]. This evidence concerns the gene PTHLH and neoplasm.