Over the past thirty years he and Miriam Moffatt have developed a successful research group devoted to understanding the genetic causes of asthma (Zhang Y. et al., Nature Genetics 2003; Allen M. et al., Nature Genetics 2003; Moffatt M. et al., Nature 2007; Moffatt M. et al., New England Journal of Medicine 2010).

Many of the genes identified by these studies are concentrated in the airway epithelium, so that asthma is now recognised as a disease of the airway mucosa. Genes identified by the group such as ORMDL3, IL33, TSLP and IL18R1 are the focus for new asthma therapies.