CD105, also known as Endoglin, is a type I transmembrane glycoprotein and a component of the transforming growth factor-beta (TGF-尾) receptor complex. It is highly expressed in proliferating endothelial cells and plays a crucial role in angiogenesis and vascular development. CD105 is upregulated in areas of active vascular growth, such as tumor tissues, wound healing sites, and inflamed tissues, making it a valuable marker for studying tumor-related angiogenesis. Additionally, it is involved in maintaining the integrity of the vascular system and regulating immune responses. In clinical applications, CD105 is used as a diagnostic marker for certain cancers and vascular diseases, and it is also a potential target for anti-angiogenic therapies.