The COL4A3 protein is an important type IV collagen component that, together with laminin, proteoglycans, and nestin/nesidin, plays a role in forming the "chicken wire" network structure in the glomerular basement membrane (GBM) . Key role. Its cleavage product tumstatin is derived from the NC1 domain of collagen α 3 (IV) and has dual anti-angiogenic and anti-tumor cell activities. COL4A3 Protein, Human (His) is the recombinant human-derived COL4A3 protein, expressed by E. coli , with N-6*His labeled tag.