The N-terminal globular domain of human platelet glycoprotein Iβα has a methionine 145/threonine 145 amino acid polymorphism which is associated with the HPA-2 (Ko) alloantigens - Kuijpers, R W A M; Faber, N M; Cuypers, H T M; Ouwehand, W H; von dem Borne, A E G Kr (J Clin Invest, 1992)