It is proposed that δ12-prostaglandin-J3 ( δ12-PGJ3) undergoes a second dehydration to form 15-deoxy-prostaglandin J3 (15d-PGJ3) (Fitzpatrick et al. 1983, Shibata et al. 2002). Oxo-fatty acids, like 15d-PGJ3, can covalently bind and activate the peroxisome proliferator-activated receptor γ (PPARγ) and inhibit pro-inflammatory cytokine and nitric oxide production (Groeger et al. 2010, Waku et al. 2009, Shibata et al. 2002, Lefils-Lacourtablaise et al. 2013). In mice, oxo-prostaglandins such as 15d-PGJ3 may have a chemopreventative effect in myeloid leukemia (Finch et al. 2015, Hedge et al. 2011).