ADAM33 and allergic respiratory disease: Several GWAS studies indicate a role of HH pathway molecules in the etiology of asthma [58, 59], and the recent study by Murk and DeWan [60] reported a possible interaction between GLI2 and the major asthma susceptibility gene ADAM33. However, as far as we know, there are no reports in the literature on differential methylation in GLI2 in relation to respiratory allergy.