It was estimated that CRP mediated 32.59% (95% CI: 17.90%, 47.27%) of the effect of BMI on pneumonia, which was higher than the proportion mediated by IL-6 (7.96% [95% CI: 1.79%, 14.14%]) and FEV1 (4.04% [95% CI: 0.34%, 7.74%]). The gene discussed is CRP; the disease is susceptibility to pneumonia measurement.