This landscape encourages the search for other pharmacological agents [38,48], also with endothelial-protective and histone-neutralizing properties in COVID-19 patients (e.g., apolipoprotein A–I, activated protein C, thrombomodulin, recombinant anti-histone IgG, peptidylarginine deiminases inhibitors, etc.)[51,52,53,54], but also to develop a circulating histone sensitive assay for laboratory medicine for better stratifying the risk of COVID-19 patients (as well as for sepsis-affected patients) [2,23]. The gene discussed is PROC; the disease is COVID-19.