PTGS2 and allergic rhinitis: Meng et al. reported that the expression of COX-2 decreased, when epigallocatechin (candidate therapeutic agent for allergy) was administered to mice with OVA-induced allergic rhinitis.[20] However, since COX-2 expression was not changed because of hypergravity in our study, we can speculate that the mechanism of the anti-allergic effect of hypergravity is independent of COX-2.