Langerhans cells (LCs) are a subset of immature dendritic cells (DCs) that specifically localize in the epidermis and other mucosal epithelia. Epidermal LCs possess strong immunostimulatory capacity and play a central role in the initiation and regulation of immune responses. Langerin (CD207) is a Ca2+-dependent, C-type lectin domain-containing, type II transmembrane protein that induces epidermal LCs to differentiate into Birkbeck granules (BG). BGs are organelles with superimposing and zippering membranes that influence proper class I type antigen presentation to the circulating T-cells. Human spleen, lymph node, thymus, liver, lung and heart express langerin protein.