Platelet activation induced by CRP-XL studied by whole blood flow cytometry. Platelet fibrinogen binding (A), P-selectin expression (B), and annexin V binding (C) were measured in CRP-XL–stimulated blood samples from donors homozygous for “aa” or “bb.” Activation markers were analyzed on CD61⁺ events. Data are expressed as the mean ± SEM, and statistically significant differences between the “aa” and the “bb” groups (Mann-Whitney U test, P < .05) are marked by asterisk.