Disclosed herein are genes which are differentially expressed in venule endothelial cells (V-ECs) compared to non-venule endothelial cells (NV-ECs) and methods and compositions relating to those genes. Also disclosed herein are methods of modulating the venuleness of an endothelial cell or microvessel, methods of modulating leukocyte trafficking, methods of modulating inflammation, methods of targeting agents to tissues based on their ability to bind to surface markers expressed in a microvessel (e.g., venules and non-venules), methods of identifying the venuleness of endothelial cells or microvessels, methods of identifying agents that modulate the venuleness of endothelial cells or microvessels, methods of identifying agents that target microvessels, methods for treating diseases associated with leukocyte trafficking, methods for treating inflammatory diseases, and compositions and kits for use in the methods.