In this study, no causal effect was observed of IL-6 and TNF-β on four measures of PUFAs and five measures of osteoporosis, suggesting that the causal effect of four measures of PUFAs on BMD was not affected by IL-6 and TNF-β, moreover IL-6 and TNF-β could not affect BMD by affecting PUFAs. The gene discussed is IL6; the disease is osteoporosis.