VEGF-D overexpression promotes lymphangiogenesis. (A-L) Expression of LYVE-1 within and at the periphery of tumor tissues is examined by immunohistochemistry. The region with the highest lymphatic vessel density is dotted in the black box (A-C and G-I) and shown at higher magnification in D-F and J-L. Mean lymphatic vessel density ± SD of three independent experiments are shown in M and N. *P < 0.01 vs. mice bearing SKOV3 or SKOV3/pcDNA xenografts. Original magnification: ×400. Scale bar = 200 μm in A-C and G-I.