With recent studies demonstrating the protective role of C3aR and C5aR in infections caused by Neisseria meningitis and Listeria monocytogenes respectively, along with evidence to support thrombosis triggered by promotion of C3a in E. coli O157:H7 infections [133,134,135], further studies are required to assert the specific role of platelet C3aR and C5aR in these infections. Here, C3AR1 is linked to infection.