Tumor cells do not damage bone tissue directly; instead, they primarily activate the RANKL/RANK (receptor activator for nuclear factor kappa B) system by producing receptor activator for RANKL, which, having bound with RANK on the surface of osteoclasts, initiates their proliferation and, in consequence, triggers their damaging effect on bones [1]. The gene discussed is TNFRSF11A; the disease is neoplasm.