We have previously demonstrated that the amino acid polymorphisms TLR5-1205C/T, NLRP3-2906A/G, and NOD2-2197A/C in PRRs in pigs, which have been shown to alter pathogen recognition and cytokine production at the cellular level, are also associated with pneumonia severity in commercial pig farms [5]. This evidence concerns the gene NOD2 and susceptibility to pneumonia measurement.