ITGB3 and Glanzmann thrombasthenia: After tamoxifen feeding, the conditional knockout mice recapitulated the Glanzmann’s thrombasthenia phenotype observed in global Itga2b−/− mice16 and Itgb3−/− mice.25 The mice exhibited enlarged spleens, significantly prolonged bleeding times compared to wild type (WT) and cItga2bfl/fl mice and their platelets demonstrated an inability to aggregate in aggregation assays (Figures 1D,E and S4A).