We found several of the genes causing ARCI and other forms of ichthyosis to be induced during keratinocyte differentiation, i.e., TGM1, ALOXE3, ALOX12B, NIPAL4, CYP4F22, ABCA12, ABHD5, PNPLA1, ELOVL4, LIPN and CERS3 (see Table 2). This evidence concerns the gene CYP4F22 and ichthyosis.