Rapid PSer externalization by oxLDL is by a calcium-dependent caspase pathway. (A) Human platelets (1 × 10⁸/mL) were pretreated with 100 μM Z-VAD–FMK or 5 μM CsA followed by 15 minutes of stimulation with 50 μg/mL oxLDL or 7 minutes stimulation with 0.1 U/mL THR in the presence of 500 ng/mL CVX. (B) Human platelets (30 × 10³/μL) were pretreated with 100 μM BAPTA-AM followed by oxLDL sensitization up to 30 minutes followed by 5 minutes of GPVI activation by 500 ng/mL CVX. (C) Gel-filtered platelets (30 × 10³/μL) from WT, CD36-null, CypD-null, or Bak/Bax double-null mice were sensitized with 50 μg/mL oxLDL up to 30 minutes followed by 5 minutes of GPVI activation with 500 ng/mL CVX or buffer as a control. Percent-positive for annexin V binding was measured by flow cytometry. Data represented as mean ± SEM and analyzed by 1-way ANOVA with Tukey posthoc analysis. **P < .01 compared to WT no stimulation (no oxLDL, no CVX). ##P < .01 compared to WT with CVX alone (no oxLDL). †P < .05, ††P < .01, compared to their respective WT with oxLDL and CVX stimulation group. N of >3 different donors in panels A and B; platelets from 3 different age-matched mice per strain in panel C.