In terms of the IL-13 rs20541 genotype, the aOR for AD rose as the number of risk factors increased (one risk factor: aOR 2.59, 95% CIs 1.04–6.45; two risk factors: aOR 5.09, 95% CIs 1.57–16.52; three risk factors: aOR 9.56, 95% CIs 0.81–112.97; trend p-value<0.01). The gene discussed is IL13; the disease is Alzheimer disease.