Ecm1 was the most highly induced gene observed in the array and previous studies reveal that, loss-of-function mutations in the human ECM1 gene leads to two skin disorders: lipoid proteinosis, a rare autosomal recessive disorder and lichen sclerosis a common acquired disorder [26]–[28], and inflammatory bowel disease, both of which have been treated with retinoids [29], [30]. This evidence concerns the gene ECM1 and lichen disease.