Lymphatics are anatomically and phenotypically normal in MR^−/− mice. (A) Examples of expression of LYVE-1 in the ears and gut of normal MR^−/− mice and their WT controls. Insets are negative control stainings with normal rabbit serum as the first-stage antibody. Bar represents 50 μm. (B) FITC-dextran was used to visualize lymphatics in the ears of healthy and tumor-bearing MR^−/− and WT mice. Lymphatics are almost exclusively peritumoral in the tumor-bearing ears. A dashed line outlines the tumor. Bar represents 100 μm. Objectives: Olympus UPlanFl 10×/0.30 Ph 1 for panel A and 4×/0.13 for panel B. (C) Density and (D) diameter of lymphatics in MR and WT mice without and with tumors. Values shown are means (± SEM).