CD209 and atopic eczema: DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN), also known as CD209, is a kind of innate immune receptor that is expressed on the surface of monocyte-derived DCs, participates in recognizing and capturing antigens, and is involved in many skin diseases, such as atopic dermatitis and psoriasis vulgaris [13–15].