Secondary malignant neoplasm of bone and bone marrow is a common complication of breast cancer and can occur in up to 80% of patients, and bone lesions in breast cancer are predominantly osteolytic.8,9,10,11 Osteolytic metastases are caused by osteoclast stimulation, which is mobilized by the increased levels of receptor activator of nuclear factor–κB ligand and inflammatory cytokines, such as interleukin 1 and tumor necrosis factor α.6,8,9,11. Here, TNF is linked to breast cancer.