CD41 is the 125 kDa alpha subunit (αIIb) of the gpIIb/IIIa (CD41/CD61) complex. It exists as a heterodimer composed of a heavy chain (gpIIbα) and a light chain (gpIIbβ) linked by a single disulfide bond. As a member of the integrin family, CD41 is predominantly expressed on platelets and megakaryocytes. It is reportedly involved in platelet aggregation and platelet adhesion to the extracellular matrix (ECM). The CD41/CD61 complex functions as a receptor for fibrinogen, fibronectin, von Willebrand factor, and thrombin.