The Use of Genomics to Map Phenotypic Heterogeneity of the Endothelium

The vascular endothelium lines the blood vessels of the body, and in man, the estimated number of individual cells comprising this line is somewhere in the order of 1-6×1013. The magnitude of the surface area of this lining is also impressive, in the order of 719m2 (1). Although scientists initially thought this cell layer was essentially an inert barrier between the blood and the tissue, this extensive “organ” is now known to carry out a diverse array of specialized functions. Moreover, these functions vary markedly from one vascular bed to another.