To accomplish these aims, in vivo fluorescence microscopy was employed to measure adhesion rates of human mammary carcinoma MDA-MB-231 in post-capillary venules of rat mesentery under flow and under the treatment of VEGF and cAMP; silver staining technique was used to identify the endothelial borders and adherent tumor cells; fluorescence immunostaining was applied to label adherens junction proteins between endothelial cells forming the microvessel wall under VEGF and cAMP treatments. Here, VEGFA is linked to breast carcinoma.