The A2 protein exerts its beneficial effect via fibrin in vivo. (A) Survival curve depicting the effect of the A2 mutant (n = 12) in LPS-treated mice as compared with LPS-treated mice with either the WT A2 protein (n = 10) or saline (n = 6). The difference is statistically significant (P < .05). (B) Kidneys were harvested at 24 hours after the administration of LPS to mice and stained for fibrin. Dark brown color depicts the fibrin deposition (yellow arrow), and randomized areas were selected for analysis using ImageJ. (C) In comparison with mice treated with the WT A2 protein, an increased fibrin deposition was notable for mice that received saline or the A2 mutant (n = 10 per group, unpaired subjects). The difference between the WT A2 and control or the A2 mutant protein was significant. A.U., arbitrary unit.