Role of MCU in procoagulant platelet generation. To test the role of MCU, Fluo-4– or Fluo-5N–loaded platelets were treated with the MCU blocker Ru360 (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 Ru360 on Fluo-4 (D) or Fluo-5N (E) fluorescence in all platelets, AnV⁺ platelets, and AnV^– platelets. **P < .01, ***P < .001 for dimethyl sulfoxide (DMSO) vs Ru360-treated platelets; 2-way analysis of variance with the Šidák multiple comparison test; n = 4.