NOD2 and Crohn disease: 38 Radlmayr Radlmayr M M Torok Torok HP HP Martin Martin K K Folwaczny Folwaczny C C The C-insertion mutation of the NOD2 gene is associated with fistulizing and fibrostenotic phenotypes in Crohn’s disease The C-insertion mutation of the NOD2 gene is associated with fistulizing and fibrostenotic phenotypes in Crohn’s disease Gastroenterology.