C5AR1 and persistent truncus arteriosus: We observed no difference in the amount of α-SMA positive vessels at 42 days after TAC in WT (WT: 240 ± 71 vessels/cm2 in sham operated WT vs. 199.2 ± 104 vessels/cm2 in WT TAC animals, p = 0.409) compared to sham operated or C5aR−/− mice (231 ± 77.6 vessels/cm2 in sham operated C5aR−/− vs. 239 ± 61 vessels/cm2 in C5aR−/− TAC animals, p = 0.810, Fig. 4d).