The angiogenesis and survival of tumor cell induced by VEGFR2 involves several complex signaling pathways,19 including PI3K/Akt signaling pathway.20 Akt is a key molecule in this signaling pathway, and plays a crucial role in regulating VEGFR2 function.21 We showed that STC2 silencing significantly inhibited the Akt and eNOS phosphorylation, and this inhibition was abolished by IGF-1, an activator of Akt/eNOS pathway. Here, KDR is linked to neoplasm.