A very-long-chain fatty acid (VLCFA) is a fatty acid with 22 or more carbons. Their biosynthesis occurs in the endoplasmic reticulum.[1] VLCFA's can represent up to a few percent of the total fatty acid content of a cell.[2]
^Jakobsson, Andreas; Westerberg, Rolf; Jacobsson, Anders "Fatty acid elongases in mammals: their regulation and roles in metabolism" Progress in Lipid Research 2006, volume 45, pp. 237-249. doi:10.1016/j.plipres.2006.01.004
^"Very-long-chain fatty acids from the animal and plant kingdoms" Rezanka, Tomas Progress in Lipid Research 1989, volume 28, pp. 147-87. doi:10.1016/0163-7827(89)90011-8