PF4 and COVID-19: Statistical modeling of the time effect on coagulation- and inflammation-related mediators revealed a decrease over time in leukocytes, neutrophils, platelets, PF4, EV counts, CRP+ EVs, TF+ EVs, and IP-10 in COVID-19 patients with a probability of >95% (Table 2; see also Supplementary Figure S3 for the time course of inflammatory mediators).