Sphingosine N-AcyltransferaseCeramidesSphingolipidsOxidoreductasesIchthyosiform Erythroderma, CongenitalFumonisinsEnzyme AssaysSphingosineSpinocerebellar DegenerationsActivating Transcription Factor 6HEK293 CellsMembrane ProteinsGene Expression Regulation, EnzymologicRNA, Small InterferingCell Line, TumorApoptosisGolgi ApparatusMass SpectrometryHomeostasisCatalysisRNA, MessengerSubstrate SpecificityMice, Knockout