IRGM and Crohn disease: Genetic studies [15]–[17] have identified allelic variants of the autophagy genes ATG16L1 (autophagy related 16-like 1) and IRGM (immunity related GTP-ases, M) as important risk factors for Crohn's disease, an autoinflammatory disease characterized by severe chronic inflammation of the gut mucosa [18], [19].