APCs expressing a similar phenotype to the APCs in medullary cords lined the capsule and trabeculae in the human axillary lymph node. Immunohistochemistry demonstrated that the APCs packed into the medullary cords expressed CD209; the majority of these APCs also expressed CD206, CD14, and CD68 (A-C). Anatomical definition was obtained by staining lymph node sections with antibodies detecting CD3 and CD21 to identify the T lymphocyte–rich paracortex and follicles, respectively (D). A sequential section probed with antibodies detecting CD209 and CD14 demonstrated that a population expressing these markers was scattered along the basement membranes of the capsule and trabeculae (E,F). This subcapsular APC population was consistently observed in all axillary lymph nodes (H) and coexpressed CD68 (G,I); a few of these cells also expressed CD206 (J). In one axillary lymph node, an unusually large number of cells expressing CD209 were detected beneath the capsule and along the trabeculae (K). Panels A to C were acquired from the same area on sequential sections as were panels D to F. M indicates medullary cords; white arrows identify the capsule (C) and trabeculae (T) (D-G, K). *Background autofluorescence. Data are representative of 4 independent experiments.