KDR and neoplasm: Fig. 2.a summarizes the 3-day time course of the tumor enhancement of a group of animals injected with the nanoprobe (group A). Following imaging, the animals were euthanized, tumors were excised, and total RNA was extracted for qRT-PCR. A significant difference in the gene levels can be observed from one animal to the next (Fig. 2.b). Some tumors displayed 3–5 times less VEGF and VEGFR-2 than others. Importantly, the relative gene expression level of each tumor strongly correlated to its tumor enhancement as imaged by mammography (Fig. 2.c and d).