Heparan sulfate is a complex carbohydrate, specifically a type of glycosaminoglycan, found in the extracellular matrix of various tissues in the body. It plays a crucial role in cell signaling, influencing processes such as cell growth, migration, and differentiation. Heparan sulfate is composed of repeating disaccharide units, which can be modified to create diverse structures. This molecule interacts with a variety of proteins, including growth factors and enzymes, facilitating important biological functions. Its presence is vital in processes like wound healing and the development of the nervous system. Abnormalities in heparan sulfate can be linked to various diseases, including cancer and genetic disorders.