HS3ST4 (Heparan Sulfate-Glucosamine 3-Sulfotransferase 4): HS3ST4 is an enzyme that modifies heparan sulfate, a crucial component of the extracellular matrix. This modification is vital for cell signaling and blood coagulation. Dysregulation of HS3ST4 can impact cellular interactions and may have consequences in cancer and vascular diseases.