Interestingly, nuclear DR5 regulates CXCR4 expression through inhibiting let-7 maturation [14,347], leading, as a consequence, to the expression of HMGA2 and CXCR4, and bone metastases formation of breast primary tumours [347,441,451] (Figure 4). The gene discussed is TNFRSF10B; the disease is neoplasm.