To better assess the capacity of the putative bacterial marker genes to differentiate between bacterial and viral infections, a ratio between the fold change ratio for each of the bacterial markers (FAM89A, S100PBP, IL-1β, IL-8) to each of three viral markers (MxA, RSAD2, IFI44L) was calculated (Fig 1). The gene discussed is FAM89A; the disease is viral infectious disease.