The A2 protein modulates the rate of fibrin formation in vitro. (A) Fibrin was formed from using 10% healthy human plasma and vehicle control or the A2 protein (0-0.5 μM), and turbidity was measured at λ 405 nm. The tracings shown are the average of 4 separate experiments. The baseline for fibrin polymerization in different experimental groups is normalized to time 0. (B) Bar graph shows the significant effect of the A2 protein in reducing the time to peak maximal absorbance in panel A. This represents 4 experiments using plasma from 2 healthy human donors (n = 4 paired participants).**P < .05 vs control (no A2), ***P < .007 vs control. OD, optical density.