NOD2 and inflammatory bowel disease: revealed a positive correlation of caspase recruitment domain-containing protein 15 (CARD15)/nucleotide-binding oligomerization domain-containing protein 2 (NOD2) gene mutation, an important intracellular pattern recognition receptor (PRR) that is expressed by dendritic cells (DCs), macrophages, and IECs [26], with ASCA expression in IBD-affected patients [27].