Glycoprotein Ib
Glycoprotein Ib (GPIb), also known as CD42,
is a component of the GPIb-V-IX complex on platelets. The GPIb-V-IX complex binds von Willebrand factor, allowing platelet adhesion and platelet plug formation at sites of vascular injury. It is deficient in the Bernard–Soulier syndrome. A gain-of-function mutation causes platelet-type von Willebrand disease. Autoantibodies against Ib/IX can be produced in immune thrombocytopenic purpura. Components include GP1BA and GP1BB. It complexes with Glycoprotein IX. References

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Glycoproteins