The top 5 of main regulators or hub genes of module 4 included genes involved in the keratinization process such as KRT78 (Keratin type II cytoskeletal 78), genes encoding calcium-binding proteins that play an antimicrobial function (S100A8, S100A9, S100A12) and TRIM29 (Tripartite Motif Containing 29) which is also involved in the response to viral and bacterial infections. This evidence concerns the gene S100A9 and bacterial infectious disease.