Collagen type III is a major fibrillar collagen that is found in extensible connective tissues such as skin, lung, and the vascular system. Recombinant human collagen type III α1 / COL3A1 has a long, inflexible, triple-helical domain and has good biocompatibility. Its functional area has a 164.88° flexible triple helix structure. It is being widely studied for clinical application in vascular endothelium, endometrium, wound, oral mucosa repair and orthopedics.