KDR and breast cancer: VEGFR2 was confirmed to have roles in breast cancer angiogenesis and the inhibitor [YLL545, a novel synthesized compound from commercially available 1H-pyrazolo[3,4-d]-pyrimidin-4(5H)-one [1] for VEGFR2 has been shown to inhibit the downstream signaling regulators such as phosphor STAT and phosphor ERK1/2 [77].