Increased levels of pro-osteoclastogenic factors such as tumor necrosis factor-alpha (TNF-α) and RANKL and more granulocyte macrophage colony-stimulating factor (GM-CSF) secreted by B lymphocytes or decreased levels of anti-osteoclastogenic factors [e.g., interferon-gamma (IFN-γ)] were associated with osteoporosis risk (16–21). The gene discussed is TNF; the disease is osteoporosis.