Anti-DLL4 binding protein

A binding protein capable of binding to DLL4, comprising one or more specified CDR domains, may be used for therapy, diagnosis or imaging. Fusion proteins and protein conjugates, nucleic acid molecules encoding the binding proteins and methods of preparing binding proteins capable of binding to DLL4 are also disclosed. The binding proteins are preferably antibodies or fragments thereof, or chimeric single change molecules. The binding proteins may be used for the treatment of diseases characterised by aberrant angiogenesis, such as cancer (especially pancreatic or prostate cancer), atherosclerosis, arthritis, ocular neovascularisation, endometriosis, uterine fibroids or pre-eclampsia.