HABP2 encodes a serine protease belonging to the peptidase S1 family.  The protease binds to hyaluronic acid and carries out the cleavage of the alpha and beta chains of fibrinogen.  It is also responsible for degrading the extracellular matrix, maintaining vascular integrity and activating the Factor VII protein.  Studies have further suggested the possibility that HABP2 acts as a tumor suppressor and protects against liver fibrosis.

Mutations in the HABP2 gene are associated with an increased susceptibility to Venous Thromboembolism, a disorder characterized by inappropriate clot formation resulting in deep vein thrombosis.  The gene is also associated with Nonmedullary Thyroid Cancer 5 (NMTC5), a carcinoma of the thyroid gland that runs in families. 

The HABP2 gene is located on the long arm of chromosome 10.  The gene is made up of 38 kb of DNA and its coding sequence consists of 14 exons.  The protein encoded by HABP2 is 62 kDa in size and contains 560 amino acids.  Alternative splicing results in an additional 59 kDa isoform, consisting of 534 amino acids.  While the gene is ubiquitous in expression, it is found to be expressed highly in the liver, synovial fluid, vitreous humor, plasma and serum.  

The mutation G534E has been associated with susceptibility to venous thrombolism and nonmedullary thyroid cancer.  The mutation occurs within the serine-protease-trypsin domain of the HABP2 protein and is believed to cause a space constraint near the catalytic region, disrupting the active site and surface accessibility of its substrates.