Intestinal epithelial cells in microbial homeostasis. Intestinal epithelial cells in microbial homeostasis. The microbiota and microbiota‐derived immune stimuli are shown in red. IECs, which are the communicators between microbiota and professional immune cells, and IEC‐mediated effects are shown in yellow. Immune cells and their influence on epithelial barrier formation and IgA‐mediated mucosal host protection are shown in blue. Please refer to the text for details. AMP, antimicrobial peptide; IEC, intestinal epithelial cell,; LPS, lipopolysaccharide; PSA, polysaccharide A; TGF‐β, transforming growth factor beta; TNF, tumour necrosis factor; TSLP, thymic stromal lymophopoietin; MIP2, macrophage inflammatory protein 2. Johanna Pott, and Mathias Hornef EMBO Rep. 2012;13:684-698 © as stated in the article, figure or figure legend