**6. SNPs in the neutrophil cytosolic factor 4 gene**

More recently, GWAS has identified a number of new genetic susceptibility factors for IBD. Of these, new candidates have confirmed the association of the proinflammatory cytokine interleukin-23 receptor subunit (IL-23R) with CD and UC and a second gene, neutrophil cytosolic factor 4 (*NCF4*) with CD [36].

Researchers, Nuij et al. [27], have demonstrated that an IBD-associated SNP in the neutrophil cytosolic factor 4 (*NCF4*) gene results in a decreased antimicrobial function of granulocytes, as demonstrated by a reduced production of reactive oxygen species by these cells [27]. Moreover, as recently shown, SNPs in the interleukin 23 receptor gene (IL23R) have affected to express the anti-microbial peptide DMBT1 in intestinal epithelial cells in IBD [27].
