VEGFA and colorectal carcinoma: Despite the fact that VEGF is the dominant factor in angiogenesis and its targeting has been an effective therapeutic strategy in CRC, pre-treatment levels of circulating VEGF levels in phase III clinical trials do not predict response to bevacizumab, nor are tumour expression levels of VEGF protein predictive of benefit to bevacizumab therapy in mCRC patients [15, 16].