This high purity monounsaturated fatty acid is ideal as a standard and for biological systems.{50604} Eicosenoic acid is formed by the elongation of oleic acid and can then be converted to docosenoic acid and nervonic acid. It is found in many plants and animals in small amounts although in some marine fish it is one of the major fatty acids. Eicosenoic acid is found in the membrane of red blood cells and the concentration is higher in children with autism making it an important biomarker.{50605} Eicosenoic acid is also found in bone marrow aspirates and phospholipids.{50606}