Several Nod-like receptor (NLR) family genes (nucleotide-binding oligomerization domain (NOD) 1, NOD2, NLRP2, NLRP3 and class II trans-activator (CIITA)) which act as intracellular sensors to detect cytosolic microbial components and "danger" signals were elevated upon infection (Figure 4 and Additional file 2, Table S1). This evidence concerns the gene NOD2 and infection.