In terms of the influence of the CRTh2 rs533116 G > A polymorphism on FEV1, the combined analysis of males and females showed a trend for significance for the AA genotype to influence risk for lower FEV1 (recessive model, p = 0.055) but, in contrast to diagnosis of severe asthma, no effect was observed in sex-stratified analysis. Here, PTGDR2 is linked to asthma.