Previous studies have demonstrated upregulated expression of Toll-like receptors (TLR) 2, 4, and 9 in different breeds of dogs with CIE (47, 48), including GSD with IBD where TLR4 was upregulated and TLR5 downregulated at the mRNA level (49). Here, TLR5 is linked to congenital non-bullous ichthyosiform erythroderma.