The glomerular endothelium is the first part of the glomerular filtration barrier that provides a barrier to albumin. In this Review, Simon Satchell describes the evidence for a role of the glomerular endothelium, and particularly the endothelial surface layer, in albumin handling. He also discusses the roles of podocytes and glomerular endothelial cells in glomerular homeostasis, and the therapeutic potential of targeting the endothelial surface layer in glomerular and vascular diseases.
