When measuring IL8 levels (Figure 1, Panels B,D,F,H,J,L,N) we observe a similar response but with a different dose–response relationship compared with the promoter–reporter (SEAP) data, that is, the presence of both the asthma risk alleles was required for maximal IL1RL1 signalling. The gene discussed is CXCL8; the disease is asthma.