Heerlen polymorphism of protein S, an immunologic polymorphism due to dimorphism of residue 460 - Bertina, R M; Ploos van Amstel, H K; Van Wijngaarden, A; Coenen, J; Leemhuis, M P; Deutz-Terlouw, P P; Van der Linden, I K; Reitsma, P H (Blood, 1990)