NOD2 and inflammatory bowel disease: In IBD, however, this equilibrium collapses due to genetic susceptibility, such as nucleotide-binding oligomerization domain-containing protein 2 (NOD2) mutations (4), environmental triggers (e.g., dysbiosis), and dysregulated immune pathways, including impaired Th2 regulation and hyperactivation of Th1/Th17 responses (5–7).