S100A8/A9 has been evaluated in dogs with CIE as a marker of early differentiated MΦ, whereby CD163 expression served as a marker for resident MΦ, showing decreased resident MΦ and increased early differentiated MΦ counts, and thus, more mucosal S100A8/A9+ cells in IRE and FRE. This evidence concerns the gene S100A8 and congenital non-bullous ichthyosiform erythroderma.