Diagnoses of asthma (β = 0.081, s.e. = 0.041, p = 0.048), eczema (β = 0.102, s.e. = 0.042, p = 0.014) or both (β = 0.127, s.e. = 0.055, p = 0.020) before the age of 10 years were all associated with increased serum IL-6 at the age of 9 years. The gene discussed is IL6; the disease is asthma.