An unknown reductase mediates the reduction of 7(S)-hydroperoxy-17(R)-hydroxydocosahexaenoic acid (7(S)-Hp-17(R)-HDHA) to AT-RvD5 (Serhan et al. 2002), the structure of which has been chemically synthesised as 7(S),17(R)-dihydroxydocosahexaenoic acid (Ogawa et al. 2017). In mice with E.coli infection, several specialized pro-resolving mediators (SPMs) including RvD5, together with antibiotics, accelerated resolution and heightened host antimicrobial responses (Chiang et al. 2012).