The present invention relates to the use of VEGF antagonists and alpha5beta1 antagonists for treating cancer and inhibiting angiogenesis and/or vascular permeability, including inhibiting abnormal angiogenesis in diseases. The present invention also relates to use of a VEGFR agonists and alpha5beta1 agonists to promote angiogenesis and vascular permeability. The present invention also relates to new anti-alpha5beta1 antibodies, compositions and kits comprising them and methods of making and using them.