Abstract: The present invention relates to isolated or recombinant mammalian endoglucuronidase enzymes, polypeptides and peptides, in particular human, murine and rat heparanases, genetic sequences encoding same and uses therefor, for example in the determination and characterisation of chemical compounds, proteins, polypeptides, small molecules and macromolecules capable of inhibiting metastasis, angiogenesis, angioplasty-induced restenosis, atherosclerosis, inflammation, promote wound healing and otherwise modulate physiological processes involving heparanase cleavage of heparan sulphate. The invention further relates to a method of altering, modifying or otherwise modulating the level of expression of mammalian heparanase in a cell. A further aspect of the invention relates to immunoreactive molecules capable of binding to and/or inhibiting mammalian heparanase, in particular monoclonal antibodies.