Email Post: Yersinia enterocolitica Invasin Protein Triggers Differential Production of Interleukin-1, Interleukin-8, Monocyte Chemoattractant Protein 1, Granulocyte-Macrophage Colony-Stimulating Factor, and Tumor Necrosis Factor Alpha in Epithelial Cells: Implications for Understanding the Early Cytokine Network in Yersinia Infections