Differential homing preferences of Wt and CCR7-deficient lymphoma cells. Localization of tumor cells within the spleen at day 6 (A) and within LNs and spleen at day 10 (B) after tumor cell transfer. Frozen sections were immunofluorescently stained for CD45.2⁺ tumor cells (red), CD3⁺ T cells (blue), and IgD⁺ B cells (green). Scale bars represent 100 μm. (C) Staining for CD45.2⁺ tumor cells (red) and for MOMA-1⁺ metallophilic macrophages (green) 13 days after transfer of Wt or CCR7^−/− Eμ-Myc tumor cells. Scale bars represent 100 μm.