To test if disruption of FcγR function by hexameric-Fc can have therapeutic relevance for ITP we used an established mouse model of ITP that involves bolus administration of an anti-platelet IgG which targets platelets for rapid phagocytic destruction43 in a similar way as observed in humans, leading to a drop in circulating platelet numbers. This evidence concerns the gene FCGR2A and autoimmune thrombocytopenic purpura.