CLDN4 and chronic obstructive pulmonary disease: Our data indicate the intratracheal LPS administration is associated with inflammation, enhanced goblet cell and EpCAM expression in the ileum and reduced claudin-4 expression in the colon Both COPD and asthma are associated with systemic inflammation, given there is a known link between intestinal inflammation, intestinal barrier dysfunction, and systemic inflammation, it is possible that changes in the ileum contribute to low-grade systemic inflammation associated with inflammatory lung conditions.