Immunohistochemistry.
For immunohistochemical staining, paraffin-embedded tissues were obtained from Human Tissue Bank of Gangnam Severance Hospital, Yonsei University College of Medicine, and were sectioned (5 μm) and stained with primary antibodies: rabbit anti-human CD138 (EP201), rabbit anti-human CD4 (SP35), rabbit anti-human CD11c (EP157), and mouse anti-human podoplanin (D2-40) (all from Cell Marque); mouse anti-human CD20 (L26) and rabbit anti-human lymphotoxin β (both from Abcam); mouse anti-human FDC (CAN.42, Thermo Fisher Scientific); and rat anti-human PNAd (MECA-79, BioLegend).