Keywords: ARCI; autosomal recessive congenital ichthyoses; CLE; corneocyte lipid envelope; EFA; essential fatty acid; LOX; lipoxygenase; eLOX3; epidermal lipoxygenase-3; EOS; esterified omega-hydroxyacyl-sphingosine; FATP4; fatty acid transport protein 4; H(P)ETE;