HS3ST4 (Heparan Sulfate-Glucosamine 3-Sulfotransferase 4): HS3ST4 is an enzyme involved in modifying heparan sulphate, a key component of the extracellular matrix. This modification plays an important role in cell signalling and blood coagulation. Dysregulation of HS3ST4 can affect cellular interactions and may have implications in cancer and vascular disorders.