Glycosyl hydrolase family 79, N-terminal domain. Family of endo-beta-N-glucuronidase, or heparanase. Heparan sulfate proteoglycans (HSPGs) play a key role in the self- assembly, insolubility and barrier properties of basement membranes and extracellular matrices. Hence, cleavage of heparan sulfate (HS) affects the integrity and functional state of tissues and thereby fundamental normal and pathological phenomena involving cell migration and response to changes in the extracellular micro-environment. Heparanase degrades HS at specific intra-chain sites. The enzyme is synthesised as a latent approximately 65 kDa protein that is processed at the N-terminus into a highly active approximately 50 kDa form. Experimental evidence suggests that heparanase may facilitate both tumour cell invasion and neovascularization, both critical steps in cancer progression. The enzyme is also involved in cell migration associated with inflammation and autoimmunity.