By modulating the RANKL to OPG ratio, the cytokines like PTH/PTHrP, IL-1, IL-6, and IL-11, indirectly or directly secreted by the tumor cells, enhance the osteoclast differentiation and maturation, which facilitates the process of osteoclast bone absorption (Weilbaecher et al., 2011). The gene discussed is IL1B; the disease is neoplasm.