Cellular architecture of normal human skin imaged by whole mount tissue microscopy. Human skin has a rich network of white blood cells (specifically dendritic cells, T cells and macrophages) which form sheaths around blood vessels. In this image, blood vessels (string-like structures stained for CD31; green), lymphatic vessels (ribbon-like structures stained for LYVE-1; blue) and T cells (stained for CD3; red) can be seen. T cells are only found around dermal blood vessels. Macrophages (stained for LYVE-1; blue) are also present. This normal cellular architecture is grossly disrupted in diseased skin (see related images). X10 magnification. Scale bar (white) represents 200 micrometres.