VWF-deficient mice display increased angiogenesis and mature blood vessel density. (A) Matrigel was injected subcutaneously into littermate control (CTL; top panels) or VWF-deficient mice (KO; bottom panels). Seven-day-old plugs were excised, sectioned, and stained with hematoxylin and eosin (left panels), or for immunofluorescence microscopy, with anti-CD31 (middle panels) or VEGFR-2 (right panels). Size bar = 20μm. (B) Cellular infiltrate was quantified in hematoxylin and eosin sections from CTL (open bars) or KO (closed bars). n = 5 KO mice and n = 6 CTL mice. (C) CTL or KO mice were culled and whole ears were removed. Ears were stained with anti–α-SMA-Cy3 and a tile scan was performed to obtain a composite image of the whole ear (left panels). Size bar = 2 mm. Blood vessels were identified, segmented, and converted to binary images (right panels). Total ear area, blood vessel area (relative to total ear area), and fractal dimensions were calculated. n = 5 KO mice and n = 7 CTL mice, Error bars indicate mean ± SEM. **P < .01 (Student t test).