TGM1 and autosomal recessive congenital ichthyosis: This study is one of the first addressing global changes in the cutaneous gene expression in ARCI patients with mutations in TGM1. The most pertinent findings are: (a) upregulation of genes involved in the formation of acylCer and CLE, all essential for skin barrier homoeostasis and incriminated in the aetiology of what might be called lipodysgenic ichthyoses; (b) increased expression of various AMPs and cytokine genes involved in antimicrobial response and regulation of immune response; and (c) effects on numerous genes affecting keratinocyte proliferation and differentiation.