CD41, also known as integrin αIIb or platelet glycoprotein IIb, is a crucial protein involved in platelet aggregation and hemostasis. It is encoded by the ITGA2B gene and forms a heterodimer with integrin β3 （CD61） to create the fibrinogen receptor on platelets. This receptor is essential for platelet aggregation, as it binds soluble fibrinogen and other ligands like plasminogen, prothrombin, thrombospondin, vitronectin, and von Willebrand factor. Mutations in the CD41 gene can lead to Glanzmann thrombasthenia, a bleeding disorder characterized by prolonged bleeding after injury. CD41 is also used as a marker to identify platelets, megakaryocytes, and hematopoietic progenitor cells.