Effects of treatment on microvessel density (MVD) in RCC xenografts. In both (A) 786-0 and (B) A498 models, sunitinib and MI-319 suppressed tumor angiogenesis. In 786-0, the effects of the two drugs were additive. Data is presented as a bar graph showing the mean MVD from six tumors in each treatment group. A representative tumor section stained for CD31 from each treatment group for 786-0 and A498 xenografts are in C and D, respectively.