CD41a, also known as platelet glycoprotein IIb, is a crucial component of the GPIIb/IIIa complex on the platelet membrane. It is a calcium-dependent protein that pairs with CD61 to form the functional fibrinogen receptor, playing a vital role in platelet aggregation and blood clotting. This complex is primarily expressed in normal platelets and megakaryocytes. Additionally, CD41a is one of the first cell surface markers indicative of hematopoietic commitment and is involved in maintaining hematopoietic stem cell activity during embryonic development.