Many of the genes induced by differentiation are also known to be mutated in autosomal recessive congenital ichthyosis (ARCI) or syndromes with congenital ichthyosis, i.e., TGM1, ALOX12B, ALOXE3, CYP4F22, NIPAL4, ABCA12, PNPLA1, CERS3, ABHD5, ALDH3A2, ELOVL4 and SPINK5 (Table 2). The gene discussed is PNPLA1; the disease is inherited ichthyosis.