They found that Lipocalin-1 and Lipocalin-15 which are thought to play a role in odorant binding, and glutathione S-transferases (GSTs), alcohol dehydrogenases, and other oxidizing enzymes, which are thought to play a role in odorant metabolism were downregulated in CRSwNP (28). This evidence concerns the gene HPGDS and chronic rhinosinusitis with nasal polyps.