Endothelial cells lining the microvasculature play a critical “gatekeeper” role in the inflammatory process through their ability to recruit circulating immune cells into tissues and foci of inflammation. Intestinal microvascular endothelial cells exhibit a strong immune response to LPS challenge. It also plays a critical regulatory role in gut inflammation. Pharmacological inhibition of NOS in activated intestinal microvascular endothelial cells resulted in a significant increase in leukocytes binding. Gene expression profile studies reveals that intestinal endothelial cells express biotinidase, which involves in biotin recycling. Human colonic microvascular endothelial cells allow performing systematic analyses of cytokine profiles with regard to mRNA expression and protein secretion.