In previous reports, evidences reveal that both asthma and BD share common immune abnormalities, such as the abnormal expressions of IL-67,8,27,28 and tumor necrosis factor-α (TNF-α).5,28 The high comorbidity between these 2 distinct diseases should be important for clinicians but in clinical practice, there remains a paucity of conclusive evidence as regards the comorbid prevalence rates. The gene discussed is TNF; the disease is asthma.