PF4 and ischemia: Comparing ischemic hindlimb muscles from platelet-specific C5aR1-deficient mice with Pf4-cre−C5ar1fl/fl control mice at day 14 after induction of ischemia, we observed increased pericyte density and enhanced pericyte coverage in platelet-specific C5aR1-deficient mice (Fig. 5f, g).