CommentaryHomeward Bound: How Do Skin Dendritic Cells Find Their Way into the Lymph System?

The success of the adaptive immune system relies upon the transport of antigens by dendritic cells (DCs) from skin via lymphatic vessels to lymph nodes where DCs present antigen to T cells. Little is known about the requirements for so-called “reverse transmigration” (RT). Torzicky et al. in this issue demonstrate that CD31, CD99, and CXCR4 play key roles in RT, suggesting that adhesion occurs in a defined sequence during the passage of DC into lymphatics.