Contribution of lipid metabolic pathways to the KEGG map of metabolism. The metabolic map was constructed based on the KEGG (Kyoto Encyclopedia of Genes and Genomes) database (http://www.kegg.jp/) 245. The graphical presentation is based on the Genome‐Linked Application for Metabolic Maps (http://glamm.lbl.gov) 246 with a minor modification that allows visualization of elongation and desaturation of palmitic‐ to stearic‐ and oleic acid, respectively. Lipid classification into eight main categories (A–H) is according to the 2005 convention on lipid nomenclature 19: A, fatty acids; B, glycerolipids; C, glycerophospholipids; D, sphingolipids; E, sterols; F, prenol lipids; G, saccharolipids. Polyketides (lipid category H) are not commonly found in mammalian hosts and are not depicted. Saccharolipids (lipid category G) are shown as a dotted line and not discussed in this review as they are not constituents of the mammalian lipidome. In this graphical pathway representation, cholesterol esters, lyso‐phospholipids and bis(monoacylglycero)phosphate (BMP) species are lacking.