The polyunsaturated fatty acid (PUFA) ω-3 cis-7,10,13,16,19-docosapentaenoic acid (DPAn-3) is an intermediate in the biosynthesis of docosahexaenoic acid (DHA) from eicosapentaenoic acid (EPA) and is also a precursor for the production of novel bioactive mediators. The proposed biosynthesis of specialised proresolving mediators (SPMs) derived from DPAn-3 is described here (Dalli et al. 2013, Hansen et al. 2017, Vik et al. 2017). The products of the ω-3 isomer were characterised based on DHA (docosahexaenoic acid) derived resolvins, protectins and maresins (Serhan et al. 2002, Bannenberg & Serhan 2010). The same biosynthetic route as DHA-derived SPMs is probably how DPAn-3 products are also formed (Dalli et al. 2013).