C5 and Sepsis: Besides platelet–neutrophil interaction and subsequent NETosis induction, it was found that also complement cleavage products, in particular, C3a and C5a anaphylatoxins could stimulate NETosis in sepsis animal models or in neutrophils stimulated by LPS or platelet-rich plasma from COVID-19 patients (60, 80, 115–117) (Table 2).