IL27 and inflammatory bowel disease: Given that IL-27-induced IRF1 and CIITA are known master regulators of MHC class I and class II gene transcription, respectively, and that the expression of IL-27 and its receptors is increased in IBD, we aimed to analyze here in detail the so far unknown functional role of IL-27 in IEC-mediated antigen presentation via MHC receptors, including a detailed analysis of involved IL-27 signaling pathways in IEC.