Updated most likely pathway for acylCer formation (November 2010). AcylCer formation requires unique biochemical steps, which include VLFA synthesis, ω-hydroxylation and ω-O-esterification. ELOVL4 and a cytochrome P-450 enzyme account for VLFA synthesis and ω-hydroxylation, respectively. Linoleic acid, an essential FA, is a predominant lipid species in ω-O-esterified FA. CE, cornified envelope; LA, linoleic acid; Sp, sphingoid base; and DGAT2, acylCoA:diacylglycerol acyltransferase 2.