CD207 is a 40 kDa type II transmembrane glycoprotein of the C-type lectin family. It binds to mannose-bearing glycoproteins and glycolipids of microbial and viral antigens, including HIV gp120. CD207 is expressed only in Langerhans cells, which are immature dendritic cells of the epidermis and mucosa, and its expression decreases during Langerhans cells maturation. Upon antigen binding CD207 localizes to the Birbeck granules, organelles present in the cytoplasm of Langerhans cells and consisting of superimposed membranes, which leads to a nonclassical antigen-processing pathway.