Activation of inflammatory pathways in human IBD. Leukocyte recruitment pathways including those for eosiniphils are activated in the affected colon in IBD. However, the functional implications of this are not known. We hypothesized that pro-inflammatory eotaxin (CCL11) dependent networks would be up regulated in the colon of pediatric patients with Ulcerative Colitis (UC), and that these would regulate eosinophil recruitment to the gut. These experiments tested differential colon gene expression relative to these pathways in healthy and UC samples. Colon biopsy samples were obtained from UC patients at diagnosis, and healthy controls. The global pattern of gene expression was determined using GeneSpring software, and biological networks were identified using Ingenuity software. Data suggested that a leukocyte recruitment network which includeds CCL11 is up regulated in pediatric UC at diagnosis. The degree of up regulation of these genes compared to healthy controls was remarkably conserved within the UC patient group, suggesting common mechanisms of mucosal inflammation.