AIEC type 1 pili and flagellae bind to the epithelial cell surface protein CEACAM6 (carcinoembryonic antigen-related cell adhesion molecule 6), which is upregulated in individuals with Crohn’s disease (Barnich et al., 2003; Barnich et al., 2007; Boudeau et al., 2001). Here, CEACAM6 is linked to Crohn disease.