Since the discovery of ABCA12 as the gene responsible for the HI phenotype, several mouse ABCA12 KO models have been developed and characterized (6, 8–10) showing good recapitulation of the human HI phenotype: hyperkeratosis, LB malformations, severe barrier dysfunction, and defective lipid homeostasis. The gene discussed is ABCA12; the disease is Hyperkeratosis.