GJB2 and ichthyosis: For instance, the expression of seven out of twelve ARCI genes was significantly increased, viz. SDR9C7, CYP4F22, ABCA12, LIPN, ALOX12B, SLC27A4 and CERS3 (0.98‐2.05 FC), as was the expression of three genes causing other types of ichthyosis, viz. GJB2, GBA and ELOVL4 (1.66‐5.69 FC).