Docosatrienoic acid is a rare ω-3 fatty acid not readily detected in normal phospholipid PUFA pools. It is a polyunsaturated version of the fatty acid docosanoic acid . Docosatrienoic acid inhibits [3H]-LTB4 binding to pig neutrophils at a concentration of 5 µM.¹ It also dose-dependently inhibits the activity of mammalian DNA polymerases and human topoisomerases I and II, potentially by binding directly to the hydrophobic region of the enzymes.² The cis configuration of the double bonds is important for this activity, and the carboxyl group is required as the methyl ester version has no activity at these enzymes.