KDR and neoplasm: For this, the BALB/c nude mice with developed A549-luc (luciferase expressing) tumors were injected with either one of the two VEGFR2 targeting cRGD-siRNAs (cRGD-siRNA1 or cRGD-siRNA2), or one of the following controls: cRGD peptide alone (cRGD), cRGD conjugated to a control non-targeting siRNA molecule (cRGD-control siRNA), siRNA targeting VEGFR2 conjugated to a control cRAD peptide (cRAD-siRNA2), cRGD conjugated to siRNA targeting non-essential for tumor growth β actin gene (cRGD-β actin siRNA), saline injection solution (saline).