However, it is important to note that the patient-based studies are not directly comparable to the mouse studies because 1) the NOD2 knockout mouse may differ phenotypically from the NOD2Leu1007fs knock-in mouse [61], and 2) only 4% of the ileal CD patients compared to 28% of colitis and 23% of control non-IBD patients, were homozygous for the ATG16L1 T300A nonrisk allele (ATG16L1NR/NR). Here, NOD2 is linked to Cowden disease.