Immunologically detected ALOXE3 and ALOX12B in humans and Aloxe3 and Alox12b in mice have a similar tissue distribution in being highly expressed in the outer, differentiated layers of the epidermis; they co-localize at the surface of keratinocytes in the stratum granulosum of mouse skin and during mouse embryogenesis appear concurrently at the onset of skin development at day 15.5.