WAS and Wiskott-Aldrich syndrome: We have previously demonstrated rapid in vivo turnover of WASP(−) platelets in a murine model of WAS [5], rapid ex vivo phagocytosis of antibody opsonized murine WASP(−) platelets, and a greater effect of opsonization on the in vivo clearance of WASP(−) vs. WT platelets [10].