– (±)14-HDHA is a hydroxydocosahexaenoic acid, an oxidized metabolite of DHA generated intracellularly by enzymatic or non-enzymatic reactions, is one of the specific substrates of 15-PGDH and can be further oxidized to the anti-inflammatory 14-oxoDHA, and in primary alveolar macrophages, 14-HDoHE itself significantly inhibits LPS-induced IL-6 mRNA expression in primary alveolar macrophages, which may be relevant to inflammatory diseases such as asthma.