In the German CD discovery cohort, the epistasis between ATG16L1 and rs4495224 was also strong, but less pronounced than that of rs7720838; the strongest interaction with rs4495224 involved rs6431660 (p = 8.37×10−5) and the coding SNP rs2241880 (p.Thr300Ala) (p = 3.81×10−4; Table 5). This evidence concerns the gene ATG16L1 and Cowden disease.