PTGER2 and allergic respiratory disease: Interestingly, PTGER2, a prostaglandin receptor with functions in both the acute phase allergy molecular motif (48) and bronchoconstriction asthma and allergic asthma molecular motif, although being reported as playing a role in the three diseases, presented a highly functional relationship to respiratory allergy and non-allergic asthma, but a moderate relationship to allergic asthma.