PNPLA2 and ichthyosis: Important progress on elucidating the ATGL-independent function of ABHD5 in epidermal lipid metabolism and skin barrier formation was made when we identified mutations in the ATGL-homologous gene patatin-like phospholipase domain-containing 1 (PNPLA1) that were linked to ichthyosis development in humans and golden retriever dogs (23).