Increased expression of COX-2 (P = 0.0087; Fig 4C) and TNFA (P = 0.0275; Fig 4D) was also observed in dogs with CIE (median: 1.6, range: 1.3–5.2 for COX-2/VIM ratio; median: 2.2; range: 1.7–9.5 for TNFA/VIM ratio) compared to the control group (median: 1.1, range: 0.5–3.0 for COX-2/VIM ratio; median: 1.1, range: 0.2–2.6 for TNFA/VIM ratio). This evidence concerns the gene PTGS2 and congenital non-bullous ichthyosiform erythroderma.