The ALOX12B gene encodes 12R-LOX, an enzyme belonging to the arachidonate lipoxygenase family. Enzymes in this family are responsible for catalyzing the stereo-specific peroxidation of free and esterified polyunsaturated fatty acids into fatty acid hydroperoxides, which can then be transformed into signaling molecules. 12R-LOX specifically catalyzes the conversion of arachidonic acid to 12R-hydroperoxyeicosatetraenoic acid (12R-HPETE). By carrying out its function, the enzyme is believed to play a key role in the ceramide biosynthetic process and the establishment of the skin barrier to water loss.