Human Hepatic Sinusoidal Endothelial Cells play multiple physiological functions and are central to many pathological processes. The liver contains two distinct endothelial cell types: vascular and sinusoidal. Sinusoidal endothelial cells (SEC) are microvascular endothelial cells with a unique phenotype reminiscent of dendritic cells and a unique function as antigen-presenting cells for CD4+ T cells.