Vascular Endothelial Growth Factor (VEGF) plays a critical role in both normal vascular growth and pathological angiogenesis and the humanized anti-VEGF antibody bevacizumab (Avastin(TM), Genentech) is used widely as a first-line therapy for colorectal cancer and other neoplastic diseases. Current methods for quantifying the activity of human VEGF, or antibodies that neutralize its activity, are bioassays based on the ability of anti-VEGF antibodies to inhibit the proliferation or migration of primary human umbilical vein endothelial cells (HUVEC) or other cells expressing VEGR receptors, following treatment of the cells with VEGF. Such assays can take several days to perform, are subject to a high degree of variation, and are difficult to validate. Reporter-gene assays based on the establishment of a stable cell line transfected with a luciferase reporter-gene placed under the control of a drug responsive chimeric promoter, provide highly sensitive and reproducible methods for quantifying drug activity. iLite? VEGF Assay Ready Cells is a human embryonic kidney cell line (HEK-293*; ATCC #CRL-1573) that have been genetically engineered and optimized to respond to VEGF with specific, proportional expression of Firefly Luciferase. Normalization of cell counts and serum matrix effects is obtained by a second reporter gene, a NanoLuc Luciferase reporter gene construct, under control of a constitutive promotor.