ADAM33 and asthma: Due to the fact that asthma-related ADAM33 SNPs do not belong to the metalloprotease domain, as well as the high level of redundancy within proteases that contribute to asthma pathogenesis through ligand cleavage and ultimately the poor specificity profile of small-molecule metalloproteinase inhibitors, the approach of inhibiting ADAM33′s expression with the pharmacological agent did not fulfill the expectations [58,60].