Detection of vIL-6 in RRV-associated lymphomas, RF, and MCD. (A) Lymphoma from RM 19185 was stained with murine monoclonal antibodies specific for RRV vIL-6 and CD20. (C) Lymphoma from animal 19286 was stained with murine monoclonal antibodies specific for RRV vIL-6 and goat antihuman IgM, and nuclei. (B,D) Isotype controls (original magnification ×630). (A) vIL-6 (green) and CD20 (red). (B) Isotype controls for vIL-6 and CD20. (C) vIL-6 (green) and IgM (red), and nuclei (blue). (D) Isotype controls for vIL-6 and IgM. (E) RF from animal 18483 was stained for vIL-6 (green), vimentin (red), and nuclei (blue). Original magnification ×630. (F) MCD lesion from animal 19455 was stained for vIL-6 (green), CD20 (red), and nuclei (blue). Original magnification ×630.