Within the coagulation pathways, the importance of targeting the complement system (CS), the kinin–kallikrein system (KKS), and the contact activation system (CAS) to curb the progression of COVID-19 to severe disease has been supported by several observational studies, and the rationale to inhibit the CS with a therapeutic candidate has been outlined by us and others (5–9). This evidence concerns the gene CS and COVID-19.