Role of SOCE in procoagulant platelet generation. To test the role of SOCE, Fluo-4– or Fluo-5N–loaded platelets were treated with the Orai1 blocker Synta-66 (10 µM), stimulated with Thr/CRP-XL in the presence of AnV-APC, and analyzed by using flow cytometry. Representative density plots are shown for Fluo-4–loaded platelets (A) or Fluo-5N–loaded platelets (B). (C) The percentage of platelets that bound AnV (***P < .001; paired Student t test). The effect of Synta-66 on Fluo-4 (D) or Fluo-5N (E) fluorescence in all platelets, AnV⁺, platelets and AnV^– platelets. *P < .05 for dimethyl sulfoxide (DMSO) vs Synta-66–treated platelets; 2-way analysis of variance with the Šidák multiple comparison test; n = 4.