Tumor angiogenesis at early stages of tumor development. BALB/c mice were intradermally inoculated with saline, CAF-HI (1.5 × 104), EPI-HI (1.5 × 104) or EPI-HI+CAF-HI (1.5 × 104 + 1.5 × 104). Mice were sacrificed 5 days after inoculation; the site of injection was exposed and viewed under a Trinocular Zoom Stereomicroscope. The graph shows the quantification of vessels per area. Vessel density was determined using a grid that was superimposed onto the photograph at the injection site.