ATG16L1 and Crohn disease: Two earlier studies, one by Cadwell et al. (2008) and another by Saitoh et al. (2008), took the next steps after the GWAS investigations by modeling in mice the effects of the Crohn's disease gene ATG16L1. This gene was already associated with autophagy, and in both studies, mice engineered with deficiencies in the Atg16L1 gene displayed gut inflammatory phenotypes not previously associated with autophagy.