Effects of PDGF and VEGF receptor kinase inhibitors on tumor vascularization.

<p>Sections of KAT-4 tumors from mice treated with vehicle, STI571 or PTK/ZK, alone or in combination were stained for endothelial cells of blood vessels by CD31 antibodies and then subjected to stereological analysis. Data are presented as means +/− SEM. Asterisks indicate statistically significant differences (p<0.05) compared to control (vehicle treatment).</p>