Nielsen et al., in their meta-analysis, estimated that in Asian countries the risk for developing asthma in CF heterozygotes was remarkably higher than among studies conducted in European countries (ORs: 2.78 vs. 1.23), suggesting that environmental and sociodemographic factors related to Asian areas might influence the association between CFTR heterozygosity and asthma [11]. This evidence concerns the gene CFTR and asthma.