Out of the upregulated genes in mice with CDI, oncostatin-M (OSM), matrix metalloprotease 8 (MMP8), triggering receptor expressed on myeloid cells 1 (Trem-1), and dual oxidase 2 (Duox2) were upregulated several folds (Table 1) and were particularly interesting due to their role in other gastrointestinal conditions [17,27,28,29,30]. The gene discussed is TREM1; the disease is clostridium difficile infection.